Masayuki YAMAMOTO, 1 * Hiroyasu MAKINO, 1a Jun-ichiro KOBAYASHI 2 AND Osamu TOMINAGA 3

Transcription

1 Blackwell Science, LtdOxford, UKFISFisheries Science Blackwell Science Asia Pty LtdDecember Original ArticleFeeding habits of juvenile flounderm Yamamoto et al. FISHERIES SCIENCE 2004; 70: Food organisms and feeding habits of larval and juvenile Japanese flounder Paralichthys olivaceus at Ohama Beach in Hiuchi-Nada, the central Seto Inland Sea, Japan Masayuki YAMAMOTO, 1 * Hiroyasu MAKINO, 1a Jun-ichiro KOBAYASHI 2 AND Osamu TOMINAGA 3 1 Kagawa Prefectural Fisheries Experimental Station, Takamatsu, Kagawa , 2 Fuyo Ocean Development and Engineering Co., Ltd, Taito, Tokyo and 3 Faculty of Biotechnology, Fukui Prefectural University, Obama, Fukui , Japan ABSTRACT: The abundance of food organisms and feeding habits of larval and juvenile Japanese flounder were examined during the period from May to August in 1999, 2000 and 2001 at the sandy Ohama beach, the central Seto Inland Sea. The food organisms collected with a sledge net consisted of 40 families from 18 orders, dominated by mysids, crangonids and gammarids. The mean densities of mysids, crangonid shrimp (Crangon spp.), gammarids and fish were 2.74, 6.74, 2.91 and 0.15 individuals/m 2, respectively. The main prey of the flounder (n = 202; range of total length mm) was mysids and small crangonid shrimp (<14 mm in body length). Prey fish availability was low, as the density of fish was low. The small crangonid shrimp was abundant, and the large crangonid shrimp, which could prey on larval flounder, was not abundant. The crangonid shrimp was important not as a predator for the flounder but as prey. The flounder preferred epifaunal mysids, Nipponomysis ornata and Anisomysis ijimai, to sand-burrowing mysids, Iiella oshimai, and avoided crangonid shrimp. KEY WORDS: Crangon spp., feeding habit, food organism, Japanese flounder, juveniles, larvae, mysids, Seto Inland Sea. INTRODUCTION Japanese flounder Paralichthys olivaceus is an important species in fisheries, stock enhancement and aquaculture. In the Seto Inland Sea, the annual catch of the species was approximately 1000 t in 2000 and more than 4 million hatchery-reared juveniles were released recently for stock enhancement. For more effective stock enhancement of this species, the feeding habits of larval and juvenile Japanese flounder and the abundance of food organisms have been investigated at various sandy beaches in Japan Generally, settled flounder feed chiefly on mysids and shift to fish as their main food source with growth. 1,2,4 6,8 12 However, when mysids are not abundant, the major item of their diet becomes amphipods and copepods with a lower juvenile growth rate. 6 The abundance of *Corresponding author: Tel: Fax: ky0554@pref.kagawa.lg.jp a Present address: Fisheries Division, Kagawa Prefectural Government, Takamatsu, Kagawa , Japan. Received 2 February Accepted 22 July mysids varies by area and year. 8,11,12 In order to estimate release points and to understand the recruitment process, it is necessary to study the relation between the feeding habits of flounder juveniles and the abundance of mysids. Information from the Seto Inland Sea is limited, with most investigations having been conducted in the Sea of Japan, the western East China Sea and the Pacific Ocean. The present paper describes the density of food organisms and the feeding habits of larval and juvenile Japanese flounder in nursery areas (i.e. sandy beaches like the one at Hiuchi-Nada, the central Seto Inland Sea). In addition, the predator prey relationship between crangonid shrimp (Crangon spp.), which are abundant in the Seto Inland Sea, 13 and small Japanese flounder was examined. MATERIALS AND METHODS Field sampling Sampling was carried out one to three times per month from May to August in at Ohama (median particle diameter = 0.2 mm), 14 the central

2 Feeding habits of juvenile flounder FISHERIES SCIENCE 1099 N Hiuchi-Nada 200m Honshu Depth:10m The Seto Inland Sea Seto Inland Sea (Fig. 1). Japanese flounder and food organisms were collected with a beam trawl (net mouth 0.3 m high and 2.0 m wide, mesh size 2.1 mm) 14 and a sledge net (net mouth 0.3 m high and 0.6 m wide, mesh size 0.76 mm), 10 respectively. The beam trawl and sledge net were towed by a boat during the daytime along 200 m and 50 m of the beach, respectively. The flounder juveniles collected by the beam trawl were preserved in 70% ethanol after 10% formalin fixation and samples of food organisms caught by the sledge net were preserved in 10% formalin. Laboratory analysis N Shikoku 133 E 135 E 5m L. 2 L.3 2m L. 1 Ohama Beach Fig. 1 Investigation lines for larvae and juveniles of Japanese flounder (L1 and L2) and food organisms (L3) during the period from 1999 to Water depth indicates the distance from the mean low spring tide to the bottom. The food organisms collected by the sledge net in 1999 and 2000 were identified to the lowest taxonomic level possible, but the samples obtained in 2001 were classified into major taxa and the number and weight of each major taxa were recorded. Crangonid shrimp in the Seto Inland Sea are composed of three species, Crangon affinis, Crangon cassiope and Crangon uritai. 15 The dominant species is Crangon uritai at the sandy beaches of the central Seto Inland Sea(Y Hanamura, unpubl. data, 2001). Density was calculated as weight and/or number of each major taxa per swept area. The body lengths of mysids and crangonid shrimp were recorded. When more than 100 individuals were obtained, 100 individuals extracted at random from the sample were measured. Additionally, in order to compare the body width of mysids with that of crangonid shrimp of the same body size, body length (distance from the level of the posterior margin of the orbit to the tip of the telson) and body width (greatest body width) of both mysids and crangonid shrimp were measured, and regression lines between body length and body width were calculated. Japanese flounder were sorted from the samples collected by the beam trawl. Total length was measured to the nearest 0.05 mm. The stomachs of the flounder were dissected under a stereomicroscope. Stomach contents were classified into major taxa and mysids were identified to the level of species. Prey were enumerated and their wet weights were measured. The body lengths of mysids, crangonid shrimp and gammarids were measured. Analyses of stomach contents An index of the relative importance of prey (IRI) 16 for each food item was calculated using the following equation: IRI = (%n %w) %F (1) where %n is the number of each prey item as a percentage of the total number of prey items identified, %w is the percentage in wet weight of each prey item, and %F is the frequency of occurrence for each prey item in the total number of stomachs examined. To assess the preference for prey, a selective index, Chesson s a selectivity for the main prey was calculated. 17 The selectivity, a i, was as follows: a i = (r i /n i )/S(r i /n i ), i = 1,... m (2) where r i and n i are the proportions by number of prey i in the diet and in the environment, respectively. This index varies between 0 and 1 with values greater than 1/m indicating a positive preference, and those less than 1/m indicating a negative preference. The value of a that represents a neutral preference is for m = 8. RESULTS Abundance of food organisms in the nursery area The food organisms collected by the sledge net in 1999 and 2000 consisted of 18 orders in 10 classes, dominated by mysidaces, amphipods, decapods, myophiurids and clypeasteroids (Table 1). Nipponomysis ornata, Iiella oshimai, Synchelidium lenorostralum (gammarids), crangonid shrimp (Crangon spp.) and Asterias amurensis were always collected and these species were abundant. The

3 1100 FISHERIES SCIENCE M Yamamoto et al. Table 1 List of food organisms collected by sledge net in Ohama in 1999 and 2000 Class Order Family Species Individual no. Weight (g) %F Gastropoda Mesogastropoda Naticidae Glassaulax didyma Cephalaspidea Philinidae Philine argentata Bivalvia Veneroida Mactridae Mactra chinensis Veneridae Ruditapes philippinarum Cephalopoda Sepioidea Sepiolidae Euprymna morsei Polychaeta Phyllodocida Glyceridae Glycera sp Nereididae Platynereis bicanaliculata Nephtyidae Nephtys neopolybranchia Polynoidae Harmothoe imbricata Spionida Spionidae Spiophanes bombyx 1 10 Ostracoda Myodocopida Vargula hilgendorfii Ostracoda spp. Malacostraca Mysidacea Mysidae Iiella oshimai Nipponomysis ornata Anisomysis ijimai Amphipoda Amphithoidae Ampithoe lacertosa Aoridae Aoroides sp Corophiidae Corophium acherusicum 4 30 Ischyroceridae Ericthonius pugnax Jassa slatteryi Dexaminidae Paradexamine micronesica 8 40 Pontogeneiidae Pontogeneia sp Pleustidae Pleustes panoplus 1 10 Lysianassidae Anonyx sp Melitidae Melita japonica Oedicerotidae Synchelidium lenorostralum Urothoidae Urothoe sp Hyalidae Hyale sp Phtisicidae Protomima imitatrix 2 20 Caprellidae Caprella scaura Caprella subtilis Caprella gigantochir Isopoda Cirolanidae Metacirolana sp Cumacea Bodotriidae Bodotria sp Diastylidae Diastylis tricincta Diastylis sp Decapoda Pasiphaeidae Leptochela gracilis Hippolytidae Eualus sp Crangonidea Crangon spp Callianassidae Callianassa japonica Diogenidae Diogenes nitidimanus Portunidae Portunus pelagicus Asterozoa Forcipulatida Asteriidae Asterias amurensis Ophiuroidea Myophiurida Ophiuridae Ophiuridae sp Echinoidea Clypeasteroida Astriclypeidae Astriclypeus manni Osteichthyes Perciformes Gobiidae Gobiidae sp Gobiesociformes Callionymidae Repomucenus sp Pleuronectiformes Paralichthyidae Paralichthys olivaceus Total 3329 %F, percent frequency of occurrence;, mean densities of mysids, gammarids, crangonid shrimp and fishes were 2.74, 2.91, 6.74 and 0.15 individuals [ind]/m 2, respectively (Table 2). Abundances of mysids and crangonid shrimp collected by the sledge net and surface water temperature are shown in Figure 2. Although a seasonal change in the abundance of mysids was not clear, mysids were not abundant at a temperature of more than 23 C. The maximum density was observed to be 12 ind/m 2 on 15 June In June when larval and juvenile flounder were abundant (M Yamamoto, unpubl. data, 2002), the density of

4 Feeding habits of juvenile flounder FISHERIES SCIENCE 1101 mysids varied by year, and was 1.60 ind/m 2 in 1999, 3.19 ind/m 2 in 2000 and 3.43 ind/m 2 in The density of crangonid shrimp also varied by year, and was low in 1999 and relatively high in 2000 and Table 2 Mean density of food organisms collected by sledge net in Ohama from 1999 to 2001 Contents n/m 2 mg/m 2 Mysids (Iiella oshimai) (1.38) (4.53) (Nipponomysis ornata) (1.28) (2.87) (Anisomysis ijimai) (0.08) (0.16) (unidentified Mysids) ( ) ( ) Gammaridea Crangon spp Callianassa japonica Brachyura Fishes Other , < The body lengths of mysids and crangonid shrimp, which were the dominant food organisms, ranged from 3.3 to 34.2 mm and from 2.4 to 10.6 mm, respectively (Fig. 3). The mean length of crangonid shrimp (10.6 mm) was significantly greater than that of mysids (5.8 mm; t-test, P < 0.01). However, most of the shrimp were smaller than 18 mm in body length (BL), and shrimp larger than 25 mm, which could prey on the flounder, 18 were few. The liner regression equations for the relationship between BL (mm) and body width (BW, mm) are expressed as follows (Fig. 4): Mysids: BW = 0.13BL 0.23 (n = 50; F-test, P < 0.01) (3) Crangonid shrimp: BW = 0.19BL 0.20 (n = 50; F-test, P < 0.01) (4) The regression lines were significantly different between species (F-test, P < 0.01). The BW of crangonid shrimp was larger than that of mysids. Table 3 Prey items of larvae and juvenile Japanese flounder collected in Ohama from 1999 to 2001 Contents %n %w %F IRI Copepods Mysids (Iiella oshimai) (15.3) (7.8) (12.2) (Nipponomysis ornata) (41.3) (26.8) (16.5) (Anisomysis ijimai) (11.9) (6.8) (5.7) (Misidae fragments) (8.2) (10.3) (23.9) Gammarids Crangon spp Callianassa japonica Brachyura Fishes (Callionymidae) (0.3) (2.2) (0.9) (Gobiidae) (0.6) (3.9) (0.9) (Fish fragments) (0.4) (2.4) (1.3) Unidentified Total n = 202; range of total length = mm; feeding incidence = 82.7%. %F, percentage frequency of occurrence; %n, percentage in number; %w, percentage in weight; IRI, index of the relative importance. Fig. 2 Densities of mysids and crangonid shrimp collected with a sledge net and surface water temperature at Ohama Beach from 1999 to 2001.

5 1102 FISHERIES SCIENCE M Yamamoto et al. Fig. 3 Body length distribution of mysids and crangonid shrimp collected with a sledge net at Ohama Beach from 1999 to Fig. 4 Relationship between body length and body width of mysids and crangonid shrimp. Stomach content of flounder The stomach contents of 202 wild larvae and juveniles ranging from 9.80 to mm in total length (TL) were examined. The feeding incidence (percentage of stomachs with food) was 82.7% (Table 3). The prey items of the Japanese flounder consisted of copepods, mysids, gammarids, decapods and fishes. Mysids were the most dominant prey item (%n, 76.7; %w, 51.7; %F, 58.9; IRI, ). Species of mysids included N. ornata, I. oshimai and Anisomysis ijimai. Crangonid shrimp were the second most dominant prey taxon (%n, 9.1; %w, 27.0; %F, 12.6; IRI, 454.9). Gammarids were the third most dominant prey taxon by number and frequency of occurrence (%n, 7.7; %w, 4.1; %F, 12.2; IRI, 144.0). Conversely, fish including callionymidae and gobiidae were the third most dominant prey taxon by weight, but were low in numerical importance (%n, 1.3; %w, 8.5; %F, 4.0; IRI, 39.2). Copepods and brachyura were minor prey. Fig. 5 Stomach composition in weight (%W) by the size of larval and juvenile Japanese flounder collected at Ohama Beach from 1999 to Table 4 Selectivities (Chesson s a) of the major food items in Ohama from 1999 to 2001 Contents Mean Range Mysids Iiella oshimai Nipponomysis ornata Anisomysis ijimai Gammarids Crangon spp Callianassa japonica Fishes Callionymidae Gobiidae The neutral preference was Mysids and gammarids predominated in the stomachs of small flounder (<20 mm TL), but with growth, the percentage of gammarids decreased, whereas that of crangonid shrimp increased (Fig. 5). Fish were observed in the stomachs of flounder more than 50 mm TL. The size relationship between Japanese flounder and their prey is shown in Figure 6. The body length of mysids consumed by flounder increased with the total length of the predator up to 30 mm. Then, the maximum size of the prey did not increase to larger than approximately 10 mm BL. The maximum size of crangonid shrimp consumed increased with growth of the predator, and flounder 52.6 mm in TL fed on prey 14.5 mm in BL. The size of gammarids consumed ranged from 2 to 4 mm BL. The mean BL of mysids and crangonid shrimp observed in the stomach were 5.0 and 8.0 mm, respectively. The mean individual weights of mysids and crangonid shrimp (w, mg) calculated from BL (mm) using the following equations (Y Hanamura, unpubl. data, 2001) were 1.00 and 9.29 mg, respectively:

6 Feeding habits of juvenile flounder FISHERIES SCIENCE 1103 japonicus, the dominant prey of flounder in Iwate Prefecture, 10 Chiba Prefecture 1 and the Sea of Japan, 11,12 were not seen in the stomachs of the flounder collected in this area. This species is dominant in the shallow waters of Tottori Prefecture 22 and Iwate Prefecture 23 and in the surf zone of Kashima-Nada. 24 However, the abundance of the species would have been low in the field, because Japanese anchovy were not observed among the food organisms and samples collected with a small triangle net in the surf zone of Hiuchi- Nada, the central Seto Inland Sea. 25 Fig. 6 Size relationship between prey (body length, BL) and predator (total length, TL). Mysids (N. ornata): w = BL (5) Crangonid shrimp (C. uritai): w = BL (6) Selective predation The selectivity (Chesson s a) of major prey items is shown in Table 4. Only the selectivity of N. ornata was significantly higher than the neutral preference (a = 1/m = 0.125; m is the number of the major food item; Wilcoxon signed-rank test, P < 0.05). The mean selectivities of A. ijimai (0.567) and gobiidae (0.167) were higher than the neutral preference, but no significant differences were observed. The mean selectivity of I. oshimai was Japanese flounder preferred N. ornata and A. ijimai to I. oshimai. Crangonid shrimp was avoided (Wilcoxon signed-rank test, P < 0.05). DISCUSSION Abundance of food organisms in the nursery area The mean densities of mysids and crangonid shrimp were 2.74 and 6.74 ind/m 2, respectively. The densities of mysids in the Sea of Japan, 8,11,19 Ono Bay and Miyako in the northern Pacific Ocean 20 are , and 90 ind/m 2, respectively. The density of crangonid shrimp in the Sea of Japan is ind/m 2. 19,21 These reports indicate that mysids are not more abundant in this study area than in the Sea of Japan and the Pacific Ocean; crangonid shrimp is more abundant in this area than in the Sea of Japan. The density of fish in the study area was 6.20 mg/m 2, which is lower than that ( mg/m 2 ) in exposed areas of Iwate Prefecture. 10 In addition, the Japanese anchovy Engraulis Relationship between Japanese flounder and food organisms The larval and juvenile Japanese flounder preyed mainly on mysids in the study area. However, the abundance of mysids was relatively low compared with that in the Sea of Japan. 8,11,12 The daily growth rate of Japanese flounder, which consumed mysids in Niigata Prefecture, was approximately 2.0 mm/ day. 8,26 The daily growth rate estimated from the shift in the mode of TL at the beaches of the central Seto Inland Sea was less than 1.0 mm/day (M Yamamoto, unpubl. data, 2002). The relation between the density of mysids and daily growth rate is important in order to evaluate the availability of food. A study of this is needed. The IRI of the prey taxa is ranked in the following order: mysids > crangonid shrimp > gammarids > fish. Generally, the main prey of the flounder on sandy beaches is mysids and larval and juvenile fish, and the abundance of crangonid shrimp is remarkably low. 1,2,4 6,8 12 The major prey of flounder in the central Seto Inland Sea was characterized by crangonid shrimp. The Japanese anchovy, which is the main prey item of large juvenile Japanese flounder in the Sea of Japan 2,11,12 and the Pacific Ocean, 1,4,10 was not observed in the stomachs of the flounder in this area. The Japanese anchovy is abundant in offshore areas of the central Seto Inland Sea. 27,28 Yamada et al. demonstrated that when mysids were not abundant, it was advantageous for juvenile flounder to shift from mysids to fish at approximately 50 mm in TL. 10 Large juveniles (>50 mm TL) were seldom caught in the field (M Yamamoto, unpubl. data, 2002). These results suggest the juvenile flounder in the central Seto Inland Sea migrate to offshore areas at approximately 50 mm TL and their main diet is fish. The selectivity value for I. oshimai was lower than that for other mysids. The other mysids, N. ornata and A. ijimai, are epifaunal mysids. 29 Iiella oshimai burrows in sand during the daytime

7 1104 FISHERIES SCIENCE M Yamamoto et al. and swims during the night. 30 The stomach content index (SCI) of larval and juvenile flounder was higher during the day than at night at Yanagihama beach in Nagasaki Prefecture 31 and Niigata Prefecture, 4 but this index was highest at dusk in Iwate Prefecture. 5 According to Takahashi et al., the SCI of many juveniles that feed on mysids increases in the night. 32 A more detailed study of the diel feeding rhythm of Japanese flounder in the field is necessary. The selectivity of crangonid shrimp was the lowest among food items. Because crangonid shrimp burrow in sand during the daytime, 26,33 flounder would have difficultly finding them. Additionally, crangonid shrimp are not as slender as mysids (Fig. 4). Therefore, it is suggested that flounder larvae and juveniles find it difficult to catch crangonid shrimp. Predation pressure on larval and juvenile Japanese flounder from large crangonid shrimp Most of the crangonid shrimp that appeared on the sandy beach at Hiuchi-Nada during the period from May to August were at most 18 mm in BL, and few large individual shrimps (>25 mm BL) were caught. This result suggests that the predation pressure on larval and juvenile Japanese flounder from large crangonid shrimp is not high. ACKNOWLEDGMENTS We are grateful to Mr Y Kameno, Ohama Fisheries Cooperative Association, and the staff of the Kagawa Prefectural Fisheries Experimental Station for their assistance in sampling and sorting. We thank Dr Y Hanamura for advice on mysids and crangonid shrimp. This work was partly supported by the Fisheries Agency of Japan. Thanks are also due to the two referees who made constructive comments on the manuscript. REFERENCES 1. Ishida O, Tanaka K, Sato S, Shoji Y. The biological research of Japanese flounder (Paralichthys olivaceus) II, the ecology of the juveniles in Tateyama Bay. Bull. Chiba Pref. Fish. Exp. Stn. 1977; 36: Imabayashi H. Feeding activities of juvenile and young bastard halibut, Paralichthys olivaceus, in the biotic community I, Intraspecific relationships in the population. Nippon Suisan Gakkaishi 1980; 46: Minami T. The early life history of a flounder Paralichthys olivaceus. Nippon Suisan Gakkaishi 1982; 48: Kato K. Study on resource management of flounder (Paralichthys olivaceus) in the northern coast of Niigata. Bull. Niigata Pref. Fish. Exp. Stn. 1987; 12: Hirota Y, Koshiishi Y, Naganuma N. Size of mysids eaten by juvenile flounder Paralichthys olivaceus and diurnal change of its feeding activity. Nippon Suisan Gakkaishi 1990; 56: Subiyanto, Hirata I & Senta T. Larval settlement of the Japanese flounder on sandy beaches of the Yatsushiro Sea, Japan. Nippon Suisan Gakkaishi 1993; 59: Ikewaki Y, Tanaka M. Feeding habit of Japanese flounder (Paralichthys olivaceus) larvae in the western part of Wakasa Bay, the Sea of Japan. Nippon Suisan Gakkaishi 1993; 59: Fujii T, Noguchi M. Feeding and growth of Japanese flounder (Paralichthys olivaceus) in the nursery ground. In: Watanabe Y, Yamashita Y, Oozeki Y (eds). Survival Strategies in Early Life Stages of Marine Resources. A. A. Balkema, Rotterdam. 1996; Noichi T. Early life history. In: Minami T, Tanaka M (eds). Biology and Stock Enhancement of Japanese Flounder. Kouseisha-kouseikaku, Tokyo. 1997; Yamada H, Sato K, Nagahora S, Kumagai A, Yamashita Y. Feeding habit of the Japanese flounder Paralichthys olivaceus in Pacific coastal waters of Tohoku district, northeastern Japan. Nippon Suisan Gakkaishi 1998; 64: Tanaka Y, Tominaga O, Tsusaki T, Nogami K, Fushimi H, Tanaka M. UJNR experimental release of Japanese flounder at Wada Bay: Feeding habit of wild and released juveniles. Bull. Natl. Res. Inst. Aquacult. Suppl. 1999; 1: Furuta S. Seasonal changes in abundance, length distribution, feeding condition and predation vulnerability of juvenile Japanese flounder, Paralichthys olivaceus, and prey mysid density in the Tottori coastal area. Nippon Suisan Gakkaishi 1999; 65: Yasuda G, Shinooka H, Kobayashi U. Study of rationalization of the shrimp fishery in Seto-inland sea. Bull. Naikai Reg. Fish. Res. Lab. 1957; 10: Yamamoto M & Makino H. Estimation of catch efficiency of the two-meter beam trawl for juvenile Japanese flounder in Hiuchi-Nada Sea. Saibai Giken 2002; 30: Hayashi K, Kim JN. Revision of the East Asian species Crangon (Decapoda: Caridea: Crangonidae). Crustacean Res. 1999; 28: Cortes E. A critical review of method of studying fish feeding based on analysis of stomach contents: application to elasmobranch fishes. Can. J. Fish. Aquat. Sci. 1997; 54: Chesson J. Measuring preference in selective predation. Ecology 1978; 59: Seikai T, Kinoshita I, Tanaka M. Predation by crangonid shrimp on juvenile Japanese flounder under laboratory conditions. Nippon Suisan Gakkaishi 1993; 59: Tanaka M, Ohkawa T, Maeda T, Kinoshita I, Seikai T, Nishida M. Ecological diversities and stock structure of the flounder in the Sea of Japan in relation to stock enhancement. Bull. Natl. Res. Inst. Aquacult. Suppl. 1997; 3: Yamada H, Nafahori S, Sato K, Musashi T, Fujita T, Nihira A, Kageyama Y, Kumagai A, Kitagawa D, Hirota Y, Yamashita Y. Specices composition and distribution pattern of Mysidacea in Pacific Ocean Coast of Japan. Bull. Tohoku Natl. Fish. Res. Inst. 1994; 56:

8 Feeding habits of juvenile flounder FISHERIES SCIENCE Mori J. Ecology of crangonid shrimp as predator. In: Senta T, Kinoshita I (eds). Biology of Larval and Juveniles Fishes in Sandy Beaches. Kouseisha-kouseikaku, Tokyo. 1998; Kimoto K, Higano J, Adachi K, Takagi N, Arai K, Terashima H, Yokoyama Y, Nagahata T. Quantitative sampling method of small demersal fish and mysids using the SCUBA net, result of sampling on sandy bottoms in shallow water in Japan. Techn. Rep. Natl. Res. Inst. Fish. Eng. 1996; 18: Yamada H, Endo Y, Musashi T, Yamashita Y. Distribution of mysids and larval anchovy as food organisms for juvenile flounder around artificial flounder reefs. Suisanzoshoku 1998; 46: Suda Y & Gomyo M. Physical environment and larval and juvenile fishes collected in the surf zone of a sandy beach. Contrib. Res. Fish. Eng. 1995; 1: Shoji J & Tanaka M. Larval and juvenile fishes collected in the surf zone of Hiuchi-nada, the central Seto Inland Sea, Japan. Suisanzoshoku 2002; 50: Seikai T, Takeuchi T, Park GS. Comparison of growth, feed efficiency, and chemical composition of juvenile flounder fed live mysids and formula feed under laboratory conditions. Fish. Sci. 1997; 63: Nagai T. Trends on catch and stock abundance indices of the Japanese anchovy in the Seto Inland. Bull. Nansei Natl. Fish. Res. Inst. 1991; 24: Shoji J, Maehara T, Tanaka M. Short-term occurrence and rapid growth of Spanish mackerel larvae in the central waters of the Seto Inland Sea. Fish. Sci. 1999; 65: Takahashi K. Distribution and migration of mysids in the surf-zone of a sandy beach. Gekkan Kaiyo Gougai 2001; 26: Takahashi K & Kawaguchi K. Diel and tidal migrations of the sand-burrowing mysids, Archaeomysis kokuboi, A. japonica and Iiella oshimai, in Otsuchi Bay, northeastern Japan. Mar. Ecol. Prog. Ser. 1997; 148: Noichi T, Kusano M, Ueki D, Senta T. Feeding habit of fishes eating settled larval and juvenile Japanese flounder (Paralichthys olivaceus) at Yanagihama beach, Nagasaki Prefecture. Bull. Fac. Fish. Nagasaki Univ. 1993; 73: Takahashi K, Hirose T, Kawaguchi K. The importance of intertidal sand-burrowing peracarid crustaceans as prey for fish in the surf-zone of a sandy beach in Otsuchi Bay, northeastern Japan. Fish. Sci. 1999; 65: Yamashita Y, Yamada H, Malloy KD, Targett TE, Tsuruta Y. Sand shrimp predation on settling and newly-settled stone flounder and its relationship to optimal nursery habit selection in Sendai Bay, Japan. In: Watanabe Y, Yamashita Y, Oozeki Y (eds). Survival Strategies in Early Life Stages of Marine Resources. A. A. Balkema, Rotterdam. 1996;