ELENA ANUFRIIEVA 1, *, MARIA HOŁYŃSKA 2 and NICKOLAI SHADRIN 1 INTRODUCTION

Transcription

1 A N N A L E S Z O O L O G I C I (Warszawa), 2014, 64(1): CURRENT INVASIONS OF ASIAN CYCLOPID SPECIES (COPEPODA: CYCLOPIDAE) IN CRIMEA, WITH TAXONOMICAL AND ZOOGEOGRAPHICAL REMARKS ON THE HYPERSALINE AND FRESHWATER FAUNA ELENA ANUFRIIEVA 1, *, MARIA HOŁYŃSKA 2 and NICKOLAI SHADRIN 1 1 Institute of Biology of the Southern Seas, 2, Nakhimov ave., Sevastopol, 99011, Ukraine 2 Museum and Institute of Zoology, Wilcza 64, Warsaw, Poland * Corresponding author: lena.anufriieva@gmail.com Abstract. The Crimean Peninsula holds a large number of hypersaline water bodies. Our studies focused on these poorly investigated habitats, and included few brackish and freshwater ponds. Seventeen species were identified, of which only 4(5) were collected from hypersaline waters sometimes with extremely high salinities (Acanthocyclops sp. copepodid, 210 ppt; Eucyclops sp. copepodid, 150 ppt; Diacyclops bisetosus and Cyclops furcifer, ppt). We also report on the occurrence of three alien thermophilic species (Eucyclops roseus Ishida, 1997, Mesocyclops isabellae Dussart et Fernando, 1988, and Mesocyclops pehpeiensis Hu, 1943) from the brackish and fresh waters of Crimea. Morphological descriptions, illustrations of the diagnostic characters and comments on relevant taxonomic issues are supplemented with discussion of the putative ways of dispersal of the alien copepods to Crimea. We provisionally reinstate Eucyclops roseus, regarded by others as a subspecies of E. agiloides (G. O. Sars, 1909), and retain the name Acanthocyclops trajani Mirabdullayev et Defaye, 2002 which was recently synonymized with A. americanus (Marsh, 1893) here considered a nomen dubium. Species accumulation curves based on our and literature data showed that significantly larger sampling efforts could yield a total of 6 8 species in the hypersaline waters and species in all types of continental waters of Crimea. Key words. Inland waters, species richness estimation, alien microcrustaceans, morphology. INTRODUCTION Crimea harbors a high landscape and biological diversity resulting from a complex geological history (Muratov et al. 1984, Apostolov et al. 1999). The Crimean fauna is a mixture of different faunistic components and belongs to two ecoregions of the Palearctic ecozone: northern Crimea is part of the Euro-Siberian region, while southern Crimea belongs to the Mediterranean Basin (Polishchuk 1998, Apostolov et al. 1999). As an example of the complex origin of the fauna, 44% of the mammal species are European, 32% are Mediterranean, and 22% are Central Asian (Apostolov et al. 1999). Cyclopidae are one of the largest and most diverse groups of copepods in inland waters (Monchenko PL ISSN Fundacja Natura optima dux doi: / X680636

2 110 E. ANUFRIIEVA, M. HOŁYŃSKA and N. SHADRIN 2003). The earliest surveys on the Crimean cyclopoids were provided by Sovinsky (1891), Lebedinsky (1904) and Velichkevich (1931). More comprehensive overviews of the Crimean copepod fauna were published by Tseeb (1947, 1961) and Ulomsky (1955). By the time V. I. Monchenko started his studies in Crimea, 25 cyclopid species had been known from the region. In a monograph of the Cyclopoida of the Ponto-Caspian basin Monchenko (2003) listed 34 taxa that he had identified himself from 103 samples from the Crimea, yet failed to find 6 other taxa previously recorded in the peninsula. Thence, according to this census (Monchenko 2003) ~ 40 cyclopid species occur in the Crimea. This species richness is highlighted when compared with that of larger areas such as Poland which is more than eleven times as large as the Crimea (51 cyclopid species) (Hołyńska 2008) and Italy (its area is similar to Poland) with a very rich subterranean fauna (101 species) (Stoch 2007). Crimea is the largest (nearly 26.5 thousands km 2 ) peninsula in the Black Sea. Northern Crimea is a steppe plain (19 thousands km 2 ), whilst the southern part (7 thousands km 2 ) is highland with three mountain ranges (the highest peak: Roman-Kosh, 1545 m a.s.l.). The climate varies from subtropical in the South Crimean Coast to semiarid in North, East and West Crimea. The summer maximum temperature can reach more than +40 C, and winter minimum to -10 C (average: -5 to +1 C). The total precipitation is mm in the coastal lowland (Sudak, Sevastopol), and reaches 1500 mm in the mountains. Natural freshwater bodies are relatively scarce in Crimea they are represented by small springs and adjacent pools, small mountain and steppe rivers/ streams, cave waters, etc. Artificial water bodies however are present in a wide variety, such as reservoirs created by dams, the North Crimean Canal which is one of the largest canal systems in Europe, ponds, decorative pools, rice fields, and other small water bodies (Oliferov and Timchenko 2005). The hypersaline water bodies constitute a very characteristic and peculiar habitat type in the region: fifty relatively large lakes and numerous small (from several to hundreds meters long) hypersaline water bodies (Shadrin 2009) are known in the peninsula. The Crimean hypersaline lakes are divided into two types: of marine origin (thalassohaline); and of continental origin (athalassohaline sulfate; the athalassohaline lakes were formed in the calderas of ancient mud volcanoes). Also, salinization process has recently started in some artificial ponds (Shadrin et al. 2012). Despite the long history of copepod studies in Ukraine (Sovinsky 1891), very little research has been done on the hypersaline lakes and, as a consequence, their fauna is still poorly understood (Apostolov et al. 1999). There are no data on Cyclopidae either; the only exceptions are records of unidentified Cyclopoida (Belmonte et al. 2012) and Acanthocyclops americanus (Marsh, 1893) (Anufriieva and Shadrin 2012) from few hypersaline lakes. Comprehensive faunistic surveys of the hypersaline waters in Crimea has begun very recently (Anufriieva and Shadrin 2012, Belmonte et al. 2012). Given the current poor state of knowledge of the hypersaline fauna in Crimea, we started a long-term biodiversity project in 2000, and from 2012 we focused on the Cyclopidae. Our first (partial) results, supplemented with data on some freshwater ponds, are presented herein. MATERIAL AND METHODS A total of 117 samples were collected from 39 water bodies in ; 100 samples were collected from hypersaline water bodies, 11 from brackish waters, and 6 from fresh waters. Fig. 1 shows a map of all sampling sites. Only 17 samples contained specimens of Cyclopidae, the characteristics of those water bodies are given in Table 1. Most of the investigated water bodies are very shallow, therefore water was collected by a 5 liter bucket. Up to L of water were filtered through plankton net with mesh size of 110 µm, the resulting samples were preserved in the field with a 4% buffered formalin solution. Salinity, temperature, and ph were measured during each sampling. Specimens were dissected in glycerin under an Olympus SZ-ST stereo microscope. Identifications and measurements were made using an Olympus BX50 compound microscope with Nomarski (differential interference contrast) optics. Drawings were prepared with the aid of a drawing tube attached to the compound microscope. The morphometric measurements were taken following Koźmiński (1936). Dissected specimens were mounted in glycerin and the semi-permanent slides were sealed with nail polish. In a few cases we could not identify the species, because only juvenile specimens were collected in the samples. Parameters of regression equations (accumulation curves) and correlation coefficients were calculated in Excel; the confidence level of the correlation coefficients was determined from the table of Müller et al. (1979). Random permutations of data were made on-line ( webcalculator.co.uk/statistics/rpermute3.htm) to calculate accumulation curves. The Chao 2 index, a nonparametric species richness estimator is calculated as S Chao2 = S obs + F 1 2 /2F 2, where: S Chao2 and S obs are the expected and observed species richness, respectively; F 1 and F 2 are the number of singletons (number of species occurring in single sample only) and doubletons (number of species occurring in two samples). In the species diagnoses the setae of the caudal rami are denoted by Roman numerals, following the scheme applied by Huys and Boxshall (1991).

3 CYCLOPIDAE IN CRIMEA 111 Reference slides are deposited in the: IBSS Institute of Biology of the Southern Seas, Sevastopol, Ukraine; MIZ Museum and Institute of Zoology PAS, Warsaw, Poland. Morphological abbreviations: P1 P4 swimming legs 1 4, exp exopodite, enp endopodite. RESULTS Cyclopidae were present in 6%, 100% and 100% of the samples collected in the hypersaline, brackish (to 30 ppt) and freshwater habitats, respectively. A total of 17 taxa were identified on species level and three taxa were identified only at the genus level, 14 of which were collected from freshwater, 8 from brackish habitats, and 4(5) from hypersaline water bodies (Table 2). Some of these taxa withstand surprisingly high salinities: Acanthocyclops sp. (copepodid, 210 ppt), Eucyclops sp. (copepodid, 150 ppt), Diacyclops bisetosus (Rehberg, 1880) and Cyclops furcifer Claus, 1857 ( ppt). Diacyclops bisetosus was the most frequent species in the hypersaline samples. We identified two species of Mesocyclops, which have never (M. isabellae Dussart et Fernando, 1988) or very rarely (M. pehpeiensis Hu, 1943), been reported from Europe. Another interesting finding was the occurrence of Eucyclops roseus Ishida, 1997 in two localities (oligohaline/fresh waters). The only European record of this species is from northern Germany (Ishida 1997, Alekseev and Defaye 2011). Acanthocyclops trajani Mirabdullayev et Defaye, 2002 is also reported in Ukraine for the first time, though previous records of A. americanus (Monchenko 2003, Anufriieva and Shadrin 2012) very likely refer to the former species. We also collected Thermocyclops oithonoides (G. O. Sars, 1863) in a spring pool (freshwater). The species is common in other parts of Ukraine, but it has never been recorded in Crimea yet (Monchenko 2003). Thus, the total number of copepod species so far identified in Crimea is 44 (or 43) (see also the taxonomical notes on E. roseus and A. trajani). We provide short diagnoses and taxonomic notes on those taxa that are new to Europe or Ukraine, and/or show previously unreported morphological peculiarities. 50 km Figure 1. Map showing all the sampling sites in Crimea (numbers 1 17 indicate sites with cyclopids. Numbers on the map correspond to the numbers of the water bodies in Table 1). Stars are sampling sites without cyclopoids.

4 112 E. ANUFRIIEVA, M. HOŁYŃSKA and N. SHADRIN Table 1. Geographic coordinates and physicochemical features of the water bodies in which Cyclopidae were present. Type of habitat: 1 athalassohaline sulfate hypersaline lake, 2 thalassohaline hypersaline lake, 3 brackish pond, 4 formerly a hypersaline lake, 5 freshwater pond, 6 spring pool, 7 pond-wetland, 8 decorative freshwater pool No. of water Water body, name body Geographical Type of Total range of factors Sampling information coordinates habitat S, ppt T, C ph Date S, ppt T, C ph 1 Achi 45 09'N 35 25'E Aygulskoye 45 59'N 34 35'E Shimakhanskoye 45 10'N 36 25'E Chersonessus Lake 44 59'N 33 39'E Pond near W corner of Lake Tobechik 45 11'N 36 18'E Aktashskoye 45 22'N 35 49'E Koyashskoye (SE part) 45 02'N 35 12'E Yanishskoye 45 07'N 36 24'E Pond near v. Chelaydinovo 45 13'N 36 22'E Pond before Vladislavovka 45 09'N 35 23'E Kuchuk-Adjigol 45 06'N 35 27'E Kuchuk-Adjigol 45 06'N 35 27'E Pond No. 1, near Yalta 44 32'N 35 27'E Pond No. 2, near Yalta 44 32'N 35 34'E Pond No. 3, near Yalta 44 32'N 35 34'E Pond No. 4, near Yalta 44 32'N 35 34'E Pond No. 5, near Yalta 44 31'N 35 35'E Pool, near Sevastopol 44 35'N 33 24'E

5 CYCLOPIDAE IN CRIMEA 113 Table 2. List of Cyclopidae species found in different water bodies of Crimea Species Number of water body in Tab Acanthocyclops sp. + + A. trajani Mirabdullayev et Defaye, A. cf. trajani Mirabdullayev et Defaye, A. vernalis (Fischer, 1853) + Cyclops sp. + C. furcifer Claus, C. strenuus Fischer, C. vicinus Uljanin, Diacyclops sp. + + D. bisetosus (Rehberg, 1880) D. bicuspidatus (Claus, 1857) + + Eucyclops sp. + + E. roseus Ishida, E. cf. speratus (Lilljeborg, 1901) + Macrocyclops albidus (Jurine, 1820) + Mesocyclops isabellae Dussart et Fernando, M. pehpeiensis Hu, Megacyclops viridis (Jurine, 1820) + + Microcyclops rubellus (Lilljeborg, 1901) + Paracyclops fimbriatus (Fischer, 1853) + Thermocyclops crassus (Fischer, 1853) + Th. oithonoides (G. O. Sars, 1863) + Cyclopoida* + Total number of species per lake * Unidentified larvae (CII, CIII) of Cyclopidae

6 114 E. ANUFRIIEVA, M. HOŁYŃSKA and N. SHADRIN TAXONOMIC ACCOUNTS Family Cyclopidae Rafinesque, 1815 Subfamily Eucyclopinae Kiefer, 1927 Eucyclops roseus Ishida, 1997 (Figs 2A F, 3A E) Eucyclops roseus Ishida, 1997: , Figs 1 3; Ishida, 1998: 24; Chang, 2009: , , Figs ; Eucyclops agiloides roseus: Alekseev and Defaye, 2011: 61 64, ? Eucyclops agiloides: Monchenko, 2003: 79 80, 83, 87. Material examined. Ukraine, Crimea: Lake Kuchuk-Ajigol, leg. E. Anufriieva, 15 April 2013, two females (IBSS A-0001, A-0002); Sevastopol, decorative pool, leg. E. Anufriieva, 23 May 2013, one female (IBSS A-0003). Other material. Iraq, South Iraq: Al Salal marsh, 20 km NW Basra, N E, lake shore, leg. S. D. Salman and M. Hołyńska, 24 March 2012, three females (MIZ 5/2014/1-3); Shatt al Arab river, Basra, N E, leg. S. D. Salman and M. Hołyńska, 21 March 2012, one female (MIZ 5/2014/4) and one male (MIZ 5/2014/5). Diagnosis. Total body length without caudal setae: 1103 µm; prosome/urosome: 1.58; cephalothorax length/ width: 1.24; genital double-somite length/width: Lateral margins of pediger 5 with hairs (Fig. 2A). Seminal receptacle typical of genus, lateral arms of anterior part slightly shorter than those of posterior part (Fig. 2A). Hyaline frill on posterior edge of genital double-somite irregularly serrated. Ventral surface of genital double-somite with 2 posterolateral sensilla. Anal somite (Fig. 2B) bearing row of small spinules on posterior margin, and 2 sensilla on dorsal surface. Proctodeum (hindgut) with single row of long hairs on both sides. Anal operculum distinct, convex (Fig. 2B). Caudal rami slightly divergent without hairs on inner margin, 5.0 times as long as wide. Longitudinal row of spinules ( serra ) present along most of outer edge of each ramus. Posterolateral (III) caudal seta with row of short spinules on outer margin and longer setules on inner margin; spinules present at insertion of seta. Relative lengths of terminal caudal setae from terminal accessory (VI) to posterolateral (III): 1.15; 7.08; 4.69; Antennule 12-segmented, last 3 segments with nearly smooth hyaline membrane (Fig. 2C). Antenna enp2 with 9 setae. Frontal surface of antennal coxobasis (Fig. 2D) ornamented with: two groups of long hairlike spinules in distal half of segment (next distal margin and proximal to medial seta), three oblique and parallel rows of spinules in proximal part; and 2 groups of shorter spinules on lateral margin. Caudal surface of antennal coxobasis (Fig. 2E) bearing: 5 strong spinules next distal margin; 6 strong spinules more proximally at height of exopodite seta; 2 longitudinal rows of spinules of similar size near lateral margin; transverse row of spinules near implantation of medial setae, and few spinules proximal to insertion of medial setae; tiny spinules proximally to longitudinal rows, and near medial margin. Maxillulary palp (Fig. 2F) two-segmented. Proximal article bearing 3 medial setae and 1 lateral seta (remnant of exopodite); anterior surface with spinules in distinct oval pattern. Distal segment, representing endopodite, armed with 3 setae. Spine formula of exp3 of P1-P4, Medial seta on P1 basipodite with short setules at whole length (Fig. 3A). Caudal surface of P2 P4 couplers (Figs 3B D) with transverse rows of hairs; pilosity most dense on P4 coupler, hairs continuous on distal margin. P4 coxopodite bearing rich ornamentation of spinules, typical of genus. Coxopodal seta with heteronomous setulation: long setules in proximal half and short setules in distal half on inner (medial) margin; setules only present in distal half on outer (lateral) margin. P4 enp3 2.3 times as long as wide. Inner apical spine of P4 enp3 1.6 times longer than outer apical spine, and 1.2 times as long as segment (Fig. 3E); inner (medial) and outer (lateral) setae not reaching tip of longer apical spine. Leg 5 (Fig. 2A) one-segmented, bearing medial spine and apical and lateral setae. Medial spine distinctly longer than segment, small spinules present at base of spine. Notes on taxonomy Eucyclops roseus was originally described from the Okinawa Island (Ryukyus), Japan (Ishida 1997), yet Ishida (1997, 1998) himself recorded this species from several distant places, such as the more northern Japanese islands (Honshu and Hokkaido), the Russian Far East (Primorskiy), northern Germany, and Lake Victoria and Lake Naivasha in Kenya. Ishida (1997) also mentioned that E. roseus might be present in China, and some of the records of E. speratus (Lilljeborg, 1901) (e.g. Tai and Chen 1979) might in fact refer to E. roseus. This species is the most frequent and abundant cyclopid in South Korean inland waters (Chang 2009). El-Shabrawy (2013) reported it from the River Nile, Lower Egypt, and from ponds and irrigation canals in the neighborhood of Cairo. The species also occurs in Sudan (G. Idris and M. Hołyńska unpublished results) and the Mesopotamian marshes (H. H. Mohammed and M. Hołyńska unpublished results). In a review of the Eucyclops serrulatus group, Alekseev and Defaye (2011) pointed to the close relationships of E. roseus and E. agiloides (G. O. Sars, 1909), and considered E. roseus as a subspecies of

7 CYCLOPIDAE IN CRIMEA 115 Figure 2. Eucyclops roseus Ishida, 1997 from decorative pool, Sevastopol, Ukraine, female: (A) pediger 5 and genital double-somite, ventral view; (B) anal somite and caudal rami, dorsal view; (C) last antennulary segment; (D) antennal coxobasis, frontal view; (E) antennal coxobasis, caudal view; (F) maxillulary palp. Scale bars = 50 µm.

8 116 E. ANUFRIIEVA, M. HOŁYŃSKA and N. SHADRIN Figure 3. Eucyclops roseus Ishida, 1997 from decorative pool, Sevastopol, Ukraine, female: (A) leg 1 coupler, coxopodite and basipodite (coxopodal seta broken), frontal view; (B) leg 2 coupler, coxopodite and basipodite, caudal view; (C) leg 3 coupler, coxopodite and basipodite, caudal view; (D) leg 4 coupler, coxopodite and basipodite, caudal view; (E) leg 4, third segment of endopodite. Scale bars = 50 µm.

9 CYCLOPIDAE IN CRIMEA 117 E. agiloides. The authors mentioned (identification key) one character [two (E. agiloides roseus) vs. one (E. agiloides s. str.) distal group of long spinules on the frontal surface of the antennal coxobasis], by which the two forms can be distinguished from each other, but they did not specify if any difference in the geographic distribution between the nominotypical subspecies and E. agiloides roseus existed. Alekseev and Defaye also provided a short diagnosis and some drawings (mouthparts were not illustrated) of E. agiloides s. str., based on specimen(s?) from Lake Malawi. In the original description (Sars 1909) the diagnosis and illustration of Eucyclops agiloides were based on a female from Lake Victoria (Victoria Nyanza) [the type locality is not Lake Malawi (Lake Nyasa), as it was stated by Alekseev and Defaye (2011)], and in the same work Sars also mentioned two other females, apparently the same species found in the southern and southwestern part of Lake Tanganyika. Sars (1909) description and drawings naturally do not report any microcharacter, yet some features (slender habitus; terminal accessory (VI) caudal seta ~ 1.6 times as long as posterolateral (III) caudal seta; terminal segment of antennule relatively short, ca. five times as long as wide; and the inner apical spine of P4 enp3 shorter than segment) might indicate that E. agiloides sensu G. O. Sars is not conspecific with the Lake Malawi specimen shown by Alekseev and Defaye (2011). The females from Crimea differ from both forms: two distal groups of long spinules are present on the frontal surface of antennal coxobasis (one group of spinules is present in E. agiloides agiloides sensu Alekseev and Defaye); the terminal accessory and posterolateral caudal setae are subequal, the terminal segment of antennule is ~ 8 times longer than wide, and the medial apical spine on P4 enp3 is 1.2 times longer than segment (terminal accessory caudal seta distinctly longer, terminal segment of antennule relatively short, and medial apical spine of P4 enp3 shorter than segment in E. agiloides agiloides sensu G. O. Sars). We do not deny a supposedly close relationship between E. agiloides G. O. Sars and E. roseus Ishida, yet as long as the morphology of E. agiloides is unsufficiently known, it is better to keep the name E. roseus rather than to sink it in the poorly-defined E. agiloides. The latter species or a form named as E. cf. agiloides have been recorded from East- North- and West Africa, several countries in Asia [Israel, Turkey, Iran, India, China and Indonesia (Sumatra, Java)] (Kiefer 1933, Dussart 1981, Dussart and Defaye 2006, Alekseev and Defaye 2011) and also from the Lesser Caucasus and Talysh region (SE Azerbaijan) (Monchenko 2003). Some of those records (cf. notes on the distribution of E. roseus at the beginning of this section) could refer to E. roseus (unless E. roseus turns to be a younger synonym of E. agiloides). Interestingly, Monchenko (2003) found E. agiloides in a spring near Mountain Chatyr-Dag (South Crimea, Crimean Mountains), whose relation to E. roseus needs to be clarified. Finally, we would like to comment a feature, the setulation pattern of P4 coxopodal seta, which was given high diagnostic value in the Eucyclops serrulatus group (Alekseev et al. 2006, Alekseev and Defaye 2011). The seta can be homonomously (holotype of E. roseus Fig. 2l in Ishida 1997), or heteronomously setulose (E. roseus in Crimea, see Fig. 3D). Also, the lack of setulation ( gap ) on the outer margin at least in proximal half of the seta is used as a diagnostic character in some species (e.g. E. serrulatus s. str.). This state is also present in some specimens of E. roseus (Crimea, see Fig. 3D; South Korea Fig. 209H in Chang 2009). We observed intra-population variation of this feature (setules can be absent or present on the outer margin in the proximal half of P4 coxopodal seta) in specimens from South Iraq (Al Salal marsh). The character state varied even in one specimen (left and right seta had different setulation), which indicate that setulation of P4 coxopodite seta sometimes is intraspecifically variable character and should be given less weight in the identification of E. roseus. Habitats. Lakes, rivers, streams, springs, wells, ponds, puddles, swamps, bogs, salt marshes and estuaries, from fresh to brackish waters (Chang 2012). Distribution. Japan, Russian Far East (Primorskiy), South Korea, China (?), Iraq, Egypt, Sudan, Kenya, Germany, [introduced?], Ukraine (Crimea) [range extension?]. Subfamily Cyclopinae Rafinesque, 1815 Acanthocyclops trajani Mirabdullayev et Defaye, 2002 (Fig. 4A G) Acanthocyclops trajani Mirabdullayev et Defaye, 2002: 14 18, Figs 24 44; Mirabdullayev and Defaye, 2004: Acanthocyclops americanus: Monchenko, 1974: ; Miracle et al., 2013: , Figs 3 6. Material examined. Ukraine, Crimea: Lake Kuchuk-Ajigol, leg. E. Anufriieva, 8 August 2012, one female (IBSS A-0004); Sevastopol, decorative pool, leg. E. Anufriieva, 23 May 2013, two females (IBSSA-0005, A-0006); Pond near v. Vladislavovka, leg. E. Anufriieva, 15 April 2013, 2 CV copepodids (IBSS A-0007, A-0008). Diagnosis. Total body length without caudal setae: 1033 µm; prosome/urosome: 1.55; cephalothorax length/width: 1.17; genital double-somite length/width: Pediger 5 and genital double-somite naked, integumental perforation pattern on dorsal surface as in Fig.

10 118 E. ANUFRIIEVA, M. HOŁYŃSKA and N. SHADRIN 4A. Genital double-somite broadly rounded in anterior part (Fig. 4A). Anal somite with continuous row of small spinules on posterior margin and with two dorsal hair-sensilla anteriorly to operculum (Fig. 4B). Longitudinal row of hairs on both sides of proctodeum. Caudal rami parallel and naked, 4.3 times as long as wide. Spinules present at implantation of posterolateral (III) caudal seta. Caudal setae with homonomous setulation. Terminal accessory (VI) seta 1.9 times as long as posterolateral (III) seta. Dorsal (VII) caudal seta 1.2 times as long as posterolateral (III) seta. Antennule 17-segmented. Antenna enp2 with 9 setae. Antennal coxobasis adorned with few robust spinules near lateral margin on frontal surface (Fig. 4C), with long basal spinules next lateral margin, and two groups of robust spinules on caudal surface (Fig. 4D). Maxilla (Fig. 4E) with 2-segmented endopodite, with two and three setae, respectively. Robust seta in front of claw-like attenuation of basal endite, bearing in middle few spinules on both edges (Fig. 4E). P1-P4 rami 3-segmented, spine formula P4 coupler (Fig. 4F) with one row of spinules, P1-P3 couplers without ornamentation on caudal surface. Caudal surface of P4 coxopodite with: intermittent row of spinules near distal margin; one row near proximal margin in middle; two oblique rows of longer and thinner spinules near, and one sensillum next to lateral margin (Fig. 4F). Leg 4 basipodite with apical hairs. P4 enp3 (Fig. 4G) ~ 2.3 times as long as wide. Inner (medial) apical spine slightly longer than outer (lateral) spine and about as long as segment. Outer seta transformed into spine and inserted at distance of 0.64 length measured from proximal margin of segment. Medial setae also modified, bearing few long setules proximally and short spinules in distal half (Fig. 4G). P6 composed of medial seta and 2 short spines (Fig. 4A). Notes on the synonymy of A. americanus and A. trajani The taxonomy of A. trajani has been closely connected to the debates about the identity of A. americanus (Marsh, 1893), therefore we provide a short overview of the history of research on the latter species. Marsh (1893) described an Acanthocyclops under the name Cyclops americanus from the littoral of three lakes (Green, Little Green, and Rush) and stagnant pools in the vicinity of Ripon, Wisconsin State in the United States. The original diagnosis and drawings show a medium-sized (1.2 mm) Acanthocyclops with genital double-somite seemingly rounded laterally, short (about 3 longer than wide) caudal rami, terminal accessory (VI) and posterolateral (III) ( the first and fourth terminal setae ) caudal setae of nearly equal length, outer apical spine on the third endopodal segment of P4 slightly longer than inner one and distinctly shorter (~ 0.6 ) than segment. No type(s) were designated in the original paper, and the depository of the Wisconsin material is unknown. The name americanus afterwards appeared in various combinations: Marsh (1910) later referred to it as Cyclops viridis americanus; Gurney (1933) reported on the occurrence of Cyclops vernalis americanus in Britain; Yeatman (1944) synonymized Marsh s species with Cyclops (Acanthocyclops) vernalis Fischer, 1853; Dussart (1969), Monchenko (1974, 2003) and Alekseev et al. (2002) considered A. americanus as a good species and found it in several places in Europe. In a revision of the robustus-vernalis group, Kiefer (1976) examined Marsh s legacy (wet material from Kansas and Alaska, and drawings labelled by Marsh as Cyclops americanus ) deposited in the National Museum of Natural History in Washington. Kiefer identified both A. robustus and A. vernalis in this material, which prompted him to synonymize A. americanus partly with A. robustus and partly with A. vernalis. Kiefer (1976: 104) also made a note of Marsh s original illustration of the genital double-somite, suggesting that the rather indefinite shape of the segment in the drawing might have been caused by the compression of the body by a cover slide. Later works, among others a recent Acanthocyclops monograph by Einsle (1996) followed Kiefer s classification. Mirabdullayev and Defaye (2002, 2004) focused on the A. robustus-like forms (genital double-somite widely rounded laterally) made further and significant contributions to the taxonomy of the robustus-complex. They redescribed the female from Lake Mjosa in Norway (the only available material identified by G. O. Sars himself Kiefer, 1976: 96) and the male of A. robustus s. str. from Lappland in Sweden, and described two new species, A. trajani and A. einslei, both widely distributed in the Holarctic. These authors re-checked the samples originally identified by Marsh and found four (!) species [A. vernalis, A. brevispinosus (Herrick, 1894) A. einslei and A. trajani] in the vials labeled as Cyclops americanus. They also pointed out that the morphology of P4 in Marsh s illustration corresponds to the one of A. vernalis, while the drawing of the genital-double somite (of the robustus-type) should be given less weight (see Kiefer s comments above). Recently, Miracle et al. (2013) did major rearrangements in the robustus-group : i) they redescribed A. robustus, based on recently collected material from Maridalsvann (presumed to be the type locality) near Oslo, and synonymized A. einslei with A. robustus; ii) designated the neotype of A. americanus from a material recently collected in a pond in Madison (~ 90 km from the collecting sites of the original description), and synonymized A. trajani with A. americanus. In our opinion both decisions were wrong, because these

11 CYCLOPIDAE IN CRIMEA 119 Figure 4. Acanthocyclops trajani Mirabdullayev et Defaye, 2002 from Lake Kuchuk-Ajigol, Crimea, Ukraine, female: (A) pediger 5 and genital double-somite, dorsal view; (B) anal somite and caudal rami, dorsal view; (C) antennal coxobasis, frontal; (D) antennal coxobasis, caudal view; (E) maxillary basis and endopodite, caudal view; (F) leg 4 coupler, coxopodite and basipodite, caudal view; (G) leg 4 endopodite 3, with heteronomous setulation of medial setae (figured separately). Scale bars = 50 µm.

12 120 E. ANUFRIIEVA, M. HOŁYŃSKA and N. SHADRIN authors overlooked existing morphological differences between A. robustus sensu G. O. Sars and A. einslei Mirabdullayev et Defaye and A. americanus sensu Marsh and A. trajani Mirabdullayev et Defaye. The presence/absence of the spinule group on the antennal coxobasis next to the exopodal seta is not the only character by which A. robustus differs from A. einslei. The posterolateral part of pediger 5 is strongly acutely produced in A. robustus, while this structure is weakly produced in A. einslei (see illustrations in Mirabdullayev and Defaye 2002, 2004); the terminal accessory (VI) caudal seta is short, times as long as the posterolateral (III) seta in A. robustus, yet times as long in A. einslei; the lateral seta on P4 enp3 is inserted at distance of segment length in A. robustus, yet segment length in A. einslei. As to the male morphology, the P6 has a medial spine that is shorter than the middle seta and about half as long as the lateral seta in A. robustus (differing from A. trajani as well, where the medial spine is slightly longer than the middle seta), while the medial spine much longer than middle seta, and almost as long as the lateral seta in A. einslei. We think that specimens from Lake Maridalsvann, used by Miracle et al. (2013) as the reference point were conspecific with A. einslei but not with A. robustus. We also think that the designation of the neotype of A. americanus, made by Miracle et al. (2013), did not fulfill at least two conditions of a valid neotype designation: the author s reasons for believing the namebearing type specimen(s) (i.e. holotype, or lectotype, or all syntypes or prior neotype) to be lost or destroyed, and the steps that had been taken to trace it or them Miracle et al. (2013) did not mention whether they tried to find and examine the depository of the original Wisconsin material which Marsh s description was based on. evidence that the neotype is consistent with what is known of the former name-bearing type from the original description and from other sources The short apical spines on the third endopodal segment of P4 in the original drawing (the longer apical spine ~ 0.6 times as long as segment in the Marsh drawing, yet ~ 0.9 times as long in the neotype), length proportion of the outer and inner apical spines (outer spine is slightly longer in the original drawing, while it is shorter in the neotype), as well as similar length of the terminal accessory (VI) and posterolateral (III) caudal setae mentioned in the original diagnosis (seta VI 2.1 times as long as seta III in the neotype) indicate that A. americanus sensu Marsh is not conspecific with the neotype designated by Miracle et al. (2013) for the former taxon. The neotype very likely is conspecific with A. trajani Mirabdullayev & Defaye. For the reasons discussed above, we decided not to accept the classification proposed by Miracle et al. (2013), and keep A. trajani as valid name, and consider A. americanus (Marsh, 1893) as nomen dubium. Habitats. Acanthocyclops trajani occurs in different kinds of water bodies including lakes, ponds, estuaries, alkali-marsh, and rice fields. Salinity range: 0 80 ppt, temperature range: C. Distribution. Europe (including also Scandinavia), Russia (including Siberia), North Africa (Algeria, Tunisia, Egypt), Middle East (Iraq unpublished data of H. H. Mohammed and M. Hołyńska), West Asia (Iran), Central Asia (Uzbekistan, Kazakhstan), and North America [Canada, U.S.A, Mexico(?) Mirabdullayev and Defaye 2002, Miracle et al. 2013]. The previous records of A. americanus in Ukraine (Monchenko 2003, Anufriieva and Shadrin 2012) likely refer to A. trajani. Diacyclops bisetosus (Rehberg, 1880) (Fig. 5A I) Cyclops bisetosus Rehberg, 1880: ; Gurney, 1933: ; Diacyclops bisetosus: Dussart, 1969: , Fig. 69; Monchenko, 1974: Material examined. Ukraine, Crimea: Lake Shimakhanskoye, leg. E. Anufriieva, 14 April 2013, one female and one CV copepodid (IBSS A-0009, A-0010); Lake Yanishskoye, leg. E. Anufriieva, 13 April 2013, three females and one CIV copepodid (IBSS A-0011, A-0012, A-0013, A-0014); Lake Aygulskoe, leg. E. Anufriieva, 12 April, 2013, one male (IBSS A-0015); pond near v. Chelaydinovo, leg. E. Anufriieva, 13 April 2013, three females and two CV copepodids (IBSS A-0016, A-0017, A-0018, A-0019, A-0020); Tobechik, pond near W corner of Lake Tobechik, leg. E. Anufriieva, 13 April, 2013, two females and two males (IBSS A-0021, A-0022, A-0023, A-0024); Lake Koyashskoye, leg. E. Anufriieva, 14 April 2013, one female (IBSS A-0025). Species identification was based on P5 morphology (Fig. 5A), segmentation of the antennule (17-segmented) and swimming legs (P1 P4 three-segmented), length proportion of the apical spines on the third endopodal segment of P4 (inner spine longer than outer one) (Fig. 5B), and length proportion of the terminal accessory (VI) and posterolateral (III) caudal setae (subequal, or seta VI slightly shorter). While other characters were stable, we found a surprisingly great variation in the shape of the seminal receptacle (Fig. 5C I). The posterior part most often is a large sac. In the anterior part two horn-like processes were formed in almost every specimen, the extension of the which (and the volume of the anterior part) varied between the specimens from different lakes, and even within specimens from the same sample (e.g. Chelaydinovo, pond) (Fig. 5D, F, I). Notes on

13 CYCLOPIDAE IN CRIMEA 121 Figure 5. Diacyclops bisetosus (Rehberg, 1880), female: (A) pediger 5, Lake Shimakhanskoye; (B) leg 4 endopodite 3, Lake Shimakhanskoye; Seminal receptacle: (C) Lake Shimakhanskoye; (D, F, I) pond near v. Chelaydinovo; (E) Lake Yanishskoye; (G) Lake Koyashskoye; (H) Tobechik (pond near west corner of the lake). Scale bars = 50 µm.

14 122 E. ANUFRIIEVA, M. HOŁYŃSKA and N. SHADRIN the presence of the anterolateral processes can be found in every monograph of the European cyclopid fauna, yet we failed to find any illustration of the variation of this feature. We speculate that the observed variation might show the different stages of the formation process of the anterolateral horns (i.e. the females reached different stages of the process) rather than reflecting individual-specific difference. Habitats. Diacyclops bisetosus often occurs in small ephemeral waterbodies, where it survives the dry period in a resting stage (likely both as copepodid V and adult stage Dussart 1969). Not rare in brackish and underground waters (cave, spring). Gurney (1933) found it in a tree-hole in England. The species has wide temperature (0 26 C), salinity (0 150 ppt), and ph ( ) tolerance. Distribution. There are numerous records in the Palearctic region, but it was also recorded from Canada (Edmonton), Cuba, Chile, Australia (incl. Tasmania), and New Zealand (Gurney 1933, Andrew et al. 1989, Ustao lu 2004, Dussart and Defaye 2006). Mesocyclops pehpeiensis Hu, 1943 (Fig. 6A I) Mesocyclops Leuckarti pehpeiensis Hu, 1943: , Fig. C; Mesocyclops pehpeiensis: Dussart and Fernando, 1988: , Figs 24 27; Guo, 2000: 34 40, Figs 2 4; Hołyńska et al., 2003: , Fig. 57. Mesocyclops ruttneri Kiefer, 1981: , Fig. 14; Reid, 1993: , Figs 3 5. Material examined. Ukraine, Crimea, Lake Kuchuk-Ajigol, leg, E. Anufriieva, 8 August 2012, one female (IBSS A-0026). The species has been described several times, therefore our diagnosis (based on the specimen from Lake Kuchuk-Ajigol) only mentions the most important species distinguishing characters. Body length without caudal setae 1210 µm; prosome/urosome: 1.7; cephalothorax length/width: 1.2. Pediger 5 (Fig. 6A) without lateral hairs. Genital double-somite 1.2 times as long as wide, no hairs. Seminal receptacle (Fig. 6B) with wide lateral arms, transverse duct-like structures meet at acute angle (V-shape) next to horseshoe-shaped copulatory pore, copulatory duct long and slightly curved right. Caudal rami (Fig. 6C) 3.6 times as long as wide, without medial hairs. Spinules present at implantation of anterolateral (II) and posterolateral (III) caudal setae. Terminal caudal setae with homonomous setulation. Relative lengths of terminal caudal setae from terminal accessory (VI) to posterolateral (III): 2.6; 5.8; 4.13; 1.0. Antennule 17-segmented, hyaline membrane on last segment with one large notch. Antenna enp2 with 7 setae. Antennal coxobasis with long longitudinal row of spinules (24) on the frontal surface, no spinules next to insertion of exopodal seta (Fig. 6D). The spinule pattern on caudal surface of antennal coxobasis (Fig. 6E) composed of: oblique row of tiny spinules near medial edge of segment; row near implantation of medial setae; few spinules near distal margin; patch at medioproximal angle; longitudinal row (11) near lateral margin, and oblique row (8) more proximally. P1 (Figs 6F H) basipodite without medial spine. Medial expansion of basipodite pilose in P1 P3 yet naked in P4. P4 coupler bearing two large (longer than wide) acute protuberances (Fig. 6I). P4 enp3 3.0 times as long as wide; inner apical spine 1.2 times as long as outer one; outer margin of inner apical spine with many teeth. P5 (Fig. 6A) as typical of the genus; apical seta 1.3 times as long as medial spiniform seta. Habitats. Eurytopic species, found also in rice field, green-house water tank, artificial water containers, and wells (Reid 1993, Hołyńska et al. 2003, Suárez-Morales et al. 2005). Geographical distribution: it is native in East-, South-, and Central Asia (Kazakhstan Uzbekistan), and probably introduced in U.S.A (District of Columbia, Mississippi and Louisiana), Cuba (Habana Province) and Mexico (Chiapas, Pacific coast) (Reid 1993, Mirabdullayev 1996, Guo 2000, Suárez-Morales et al. 2005, Dussart and Defaye 2006). In Europe it was only known (under the name Mesocyclops ruttneri Kiefer, 1981, a younger synonym of M. pehpeiensis) from warm water basin in the botanical garden in Vienna. The Crimean record is the first finding of the species in a natural water body in Europe. Mesocyclops isabellae Dussart et Fernando, 1988 (Fig. 7A J) Mesocyclops isabellae Dussart et Fernando, 1988: , Figs 12 17; Hołyńska et al., 2003: , Fig. 74. Material examined. Ukraine, Crimea, pond near village Chelaydinovo, leg. E. Anufriieva, 13 April 2013, one female (IBSS A-0027). Diagnosis. Pediger 5 dorsally and laterally pilose (Fig. 7A). Genital double-somite with shallow integumental pits ventrally, and dorsally pilose in anterior half (Fig. 7B). Seminal receptacle with wide lateral arms, transverse duct-like structures meet at straight angle next to copulatory pore, copulatory duct short (Fig. 7C). Posterior margin of anal somite with spinules on ventral surface only (Fig. 7D). Caudal rami (Fig. 7D) 3.5 times as long as wide, without hairs on inner margin. No spinules at implantation of anterolateral (II) and posterotlateral (III) caudal setae. Length proportion of terminal caudal setae from terminal accessory

15 CYCLOPIDAE IN CRIMEA 123 Figure 6. Mesocyclops pehpeiensis Hu, 1943 from Lake Kuchuk-Ajigol, Crimea, Ukraine, female: (A) leg 5; (B) seminal receptacle; (C) anal somite and caudal rami, ventral view; (D) antennal coxobasis, frontal; (E) antennal coxobasis, caudal view; (F) leg 1 coxopodite and basipodite, frontal view; (G) leg 1 exopodite; (H) leg 1 endopodite; (I) leg 4 coupler, frontal view. Scale bars = 50 µm.

16 124 E. ANUFRIIEVA, M. HOŁYŃSKA and N. SHADRIN Figure 7. Mesocyclops isabellae Dussart et Fernando, 1988 from pond near v. Chelaydinovo, Crimea, Ukraine, female: (A) pediger 5, dorsal view; (B) genital double-somite, dorsal view; (C) genital double-somite, ventral view; (D) anal somite and caudal rami, ventral view; E, antennule, last segment; (F) antennule, segments 12 14; (G, H) antennal coxobasis, caudal view; (I) leg 4 coupler, coxopodite and basipodite, frontal view; (J) leg 4 endopodite 3. Scale bars = 50 µm.

17 CYCLOPIDAE IN CRIMEA 125 (VI) to posterolateral (III): 3.0; broken seta; 4.2; 1.0. Dorsal (VII) caudal seta 1.1 times as long as posterolateral (III) seta. Antennule 17-segmented; serrate hyaline membrane of terminal segment, extending beyond insertion of medial seta of segment, with one large subapical notch (Fig. 7E). Spinules present on antennular segments 1, 4 5, and 7 14 (Fig. 7F). Antenna enp2 with 7 setae. Spinule ornamentation on caudal surface of antennal coxobasis is similar to that in M. pehpeiensis but: spinules (19, 21) in longitudinal row near lateral margin distally conspicuously increasing in size (Figs 7G, H); and additional group of tiny spinules present between longitudinal and proximal oblique rows (Fig. 7G). P1 basipodite lacking medial spine. P4 coupler naked on frontal and caudal surfaces (Fig. 7I shows frontal surface), distal margin bearing two small and acute protuberances. Medial expansion of P4 basipodite bearing apical hairs and transverse row of hairs on caudal surface, near proximal margin. P4 enp3 (Fig. 7J) 2.9 times as long as wide, medial and lateral apical spines subequal, lateral edge of medial (inner) spine with many fine spinules. Leg 5 (Fig. 7C) typical of genus; apical seta 1.3 times as long, and lateral seta 0.9 times as long as spiniform medial seta. Notes. Mesocyclops leuckarti (Claus, 1857), a common species in European freshwaters, can be distinguished from both Mesocyclops species here recorded by the wide, short and sinuously curved copulatory duct, and the spinular ornamentation of the antennule (spinules present on segments 1, 4 5, 7 10, and 12 13). Habitats. Lakes, reservoirs, temporary pools, marshes. Temperature tolerance: 10 to 39.5 C, Salinity tolerance: 7 to 17 ppt (Mohammed et al. 2008). Mohammed et al. (2011) observed diapause in copepodid IV and V instars found at a depth of cm during winter (12 14 C) in southern Iraq. This species cannot reproduce if the temperature drops below 10 C (Mohammed et al. 2008). Distribution. South (Sri Lanka, India, Nepal, Bangladesh) and West Asia (Iraq) (Hołyńska et al. 2003, Mohammed et al. 2008), Ukraine (Crimea) [range extension?]. DISCUSSION Alien cyclopid species in Crimea and Europe We found three cyclopid species in Crimea (i.e.: Mesocyclops pehpeiensis, M. isabellae, and Eucyclops roseus) which had not yet been reported from Ukraine. The findings of Acanthocyclops trajani in oligohaline- and fresh waters in East and South Crimea very likely are not new records, because this same species could be reported as Acanthocyclops americanus from different areas of Ukraine (Monchenko 1974, 2003) including Crimea (Anufriieva and Shadrin 2012). It is also possible that Monchenko s report (2003) on the occurrence of Eucyclops agiloides in Chatyr- Dag (Crimean Mts.) in fact refers to the species that we identified as E. roseus from the East and South Crimean coast. Considering that both the fresh- (Monchenko 2003) and saline/hypersaline waters (our data) have already been sampled in Crimea rather extensively, we suppose that E. roseus is not very common in the peninsula. The only other European record of E. roseus is from northern Germany (a stream in Oldenburg) (Ishida 1997). In a review of the world distribution of the E. serrulatus-group, which E. roseus belongs to, Alekseev and Defaye (2011) did not mention any other European localities for E. agiloides roseus (they considered E. roseus as a subspecies of E. agiloides). They also stated that E. agiloides is a tropical/subtropical species, and E. agiloides roseus was introduced to northern Germany by human agency. As to Crimea, we speculate that E. roseus reached the peninsula via Caucasia from Western Asia (Iran) in a gradual process (range extension) rather than as a result of human-mediated introduction because there is no aquaculture activities in the studied water bodies. Monchenko s report (2003) on the occurrence of E. agiloides in the Lesser Caucasus and Talysh region (SE Azerbaijan) might support a southeastern dispersal route. There are no records of the genus Mesocyclops in the earlier fauna studies of Crimea. This predominantly (sub)tropical genus is also absent in the Iberian peninsula and in southern Italy and Greece (Van de Velde 1984). The first report for Crimea of the occurrence of M. leuckarti Claus, 1857, one of the commonest species in the temperate/cold temperate waters of Eurasia (incl. large part of Ukraine), was that from the Simferopol Reservoir in (Tseeb 1961). Mesocyclops leuckarti was probably the first alien cyclopid species recorded in Crimea; it could have been accidentally introduced into the Simferopol Reservoir, or transported by the North Crimean Canal (Tseeb 1961, Monchenko 2003). In this survey we found two tropical/subtropical species (M. isabellae and M. pehpeiensis) which are alien species not only in Crimea but also in Europe. A range extension cannot be excluded in these taxa either, yet the closest known occurrences of these species are from fairly distant regions: northern Karakalpakstan in Uzbekistan (ca km) in M. pehpeiensis, and southern Iraq (ca km) in M. isabellae. In the sites where M. pehpeiensis (recently desalinated fresh lake)

18 126 E. ANUFRIIEVA, M. HOŁYŃSKA and N. SHADRIN and M. isabellae (a brackish pond) live, there is no human agency that could lead to introductions of alien species. Long-distance transportation by birds seems to be more plausible explanation for the appearance of M. isabellae and M. pehpeiensis in Crimea. Crimea lies in the crossroads of important bird migration routes between the Western and Eastern Palearctic, Africa and Asia (Shadrina et al. 2002, Maclean et al. 2009, Khomenko and Shadrin 2009), which might facilitate a connection of the crustacean fauna of Crimea to Western and Central Asia, and Siberia. The case of the anostracan crustacean, Artemia urmiana Günther, 1899 (Khomenko and Shadrin 2009, Shadrin et al. 2012) is an example for such distribution pattern. Artemia urmiana occurs in Lake Urmia (Iran), in some hypersaline lakes in Crimea and in few soda lakes in Altai (Siberia); all these sites lay along the same migratory route of several migrant waterfowl species. There are at least 3 bird species (Tadorna tadorna (Linneaus, 1758), Tringa totanus (Linneaus, 1758) and Recurvirostra avosetta (Linneaus, 1758)) which might transport the brine shrimp cysts, as well as resting stages of other aquatic animals between Western (Iran) and Central Asia and Crimea (Khomenko and Shadrin 2009). The presence of resting stage that might survive such a long travel has been demonstrated in M. isabellae (CIV and CV stages) (Mohammed et al. 2011). We are not aware of any study proving the occurrence of resting stage in M. pehpeiensis, yet this Oriental species has been found in several localities (ricefields, urban ponds) in North and Central America, outside its native distributional range, which hints that some dormant stage resistant to lack of free water might exist. Interestingly, in the western hemisphere also birds were presumably transporting two Neotropical Mesocyclops species [M. longisetus (Thiébaud, 1912) and M. venezolanus Dussart, 1987] to arctic Canada (Yukon Territory) (Reid and Reed 1994). Eucyclops roseus, M. isabellae and M. pehpeiensis are thermophilic species, therefore occurrence of these cyclopids might be an indication of the effect of the climate warming on the copepod fauna of Ukraine (and Europe), although we need to collect more data to verify this hypothesis in a wider time scale. Not only the biological properties of the potential colonizers determine the success in a new environment, but also the immunity of the invaded ecosystem; destabilized or new ecosystems in the shallow water bodies have very low ecological resilience (Shadrin 2000, Gomoiu et al. 2002). It should be noted that in our case all alien species were found in newly formed water bodies where stable communities did not exist. The pond in the quarry of the former Kamysh-Burun ore mine near the village of Chelyadinovo, where M. isabellae was found, was naturally filled with rainwater in the last years. Lake Kuchuk-Adjigol, investigated by us since 2003, was a hypersaline lake before 2012 and it now hosts M. pehpeiensis, E. roseus and A. trajani. A dramatic desalination occurred in 2012 due to leakage from a freshwater reservoir filled from the North Crimean Canal. All the hyperhaline fauna previously existing there disappeared, which created empty niches for the new incomers. The other site of E. roseus is a decorative artificial pool near Kazachija Bay. Mesocyclops pehpeiensis and M. isabellae are both predator forms which naturally influence the density and species composition of their preys (cladocerans, rotifers, and dipteran larvae Dieng et al. 2003, Nagata and Hanazato 2006, Mohammed et al. 2008, Sarma et al. 2013). These alien predator cyclopids may change the zooplankton composition in their new habitats, further destabilizing ecosystems and opening doors for new incomers. We need to mention that although the problem of biological invasions is becoming a rapidly-growing research area, there is a large gap in the studies of the invasions of cyclopids in Europe and worldwide. In a recent review of the invasions of exotic species in Europe there is no information pertaining to Cyclopoida (Leppäkoski et al. 2002, Nentwig 2009). In the Global Invasive Species Database ( we have not found any data on invasive cyclopoids either. This gap should be filled in the near future. Species richness of Crimean Cyclopidae Obviously, not all species of Cyclopidae occurring in Crimea have been recorded yet, so the question is to what degree the cyclopid fauna of the peninsula has been explored? There is a fairly tight correlation between the number of samples analyzed and the number of observed species (Pesenko 1982, Shen et al. 2003, Brucet et al. 2009). Various types of functions are used to describe the relationship between the sampling effort (the number of identified specimens, or the number of samples) and the observed species richness; the power and logarithmic functions are the most used. Relying upon our own and Monchenko s (2003, Table 28) data, we found that the species accumulation curve for the whole fauna (including both fresh and saline/hypersaline waters) (Fig. 8A) is best described by the following logarithmic function (R = 0.976, p <0.0001): Y = ln(x) (1) where Y the number of observed species, ln(x) logarithm of the number of analyzed samples.