Songklanakarin Journal of Science and Technology SJST R1 Amornsakun

Transcription

1 Some aspects in early life stage and female spawner of swamp eel, Monopterus albus Journal: Songklanakarin Journal of Science and Technology Manuscript ID SJST-0-0.R Manuscript Type: Original Article Date Submitted by the Author: -Jul-0 Complete List of Authors: Amornsakun, Thumronk; price of Songkla University, Keyword: Fecundity, Yolk absorption, Mouth development, Start of feeding, Swamp eel, Monopterus albus

2 Page of Female biology and early life aspect of swamp eel, Monopterus albus Thumronk Amornsakun *, Ponpanom Promkaew and Anuar bin Hassan Fisheries Technology Program, Department of Technology and Industries Faculty of Science and Technology, Prince of Songkla University, Pattani Campus, Pattani, Thailand 000. * Corresponding author. E mail address: thumronk.a@psu.ac.th thumronk.a@gmail.com Pattani Inland Fisheries Development Center Yarang, Pattani Faculty of Fisheries and Aqua-Industry Universiti Malaysia Terengganu Mengabang Telipot, Kuala Terengganu, Malaysia 00 Abstract The sexual maturity of female swamp eel, Monopterus albus was studied by determining its fecundity and gonadosomatic index (GSI). It was found that the size of a sexually matured female swamp eel was 00-0 g in body weight. The egg s type were non adhesive demersal and rounded. The maximum fecundity was found in June at 0 ova/fish with gonadosomatic index (GSI) of.0 %. The minimum fecundity was recorded ova/fish as in October with gonadosomatic index (GSI) of 0. %. The average diameter of egg was, µm. Overall, the sizes of the fish eggs can be classified into seven groups (based on its diameter), which were 0-0 µm (. %) as group, -,0 µm (. %) as group,,-,0 µm (. %) as group,,-,0 µm (.0 %) as group,,-,0 µm (. %) as group,,-,0 µm ( %) as group, and,-,0 µm ( %) as group. Newly hatched larvae of swamp eel were produced by semi-control natural method. The newly hatched larvae were sized in. ± 0.0 cm in total length (TL), with yolk sacs volume of,.±0.0 µm. The yolk sacs were completely absorbed within hours after hatching (hah) time at water temperature of -0. C. All the larvae were able to open mouths at 0 hah (.0 ± 0. mm TL), with the height measurement of.00 ± 0. µm. The digestive tract was straight, and it is placed on the yolk sac. The digestive tracts were formed at hah with length of.00 ± 0. µm. The average number of Moina in the digestive tract at the start of feeding was 0. individual/larva. Larvae died within,0 hah at water temperature ranged between.0 to 0. C. It was found that the feeding scheme of larval swamp eel were as follows: larvae of age - days (total length.-.0 cm) consumed Moina., but at of age - days (average total length.-.0 cm) the larvae consumed both Moina and a commercial pellet known as power feed. Larvae that at more than -day old (average total length.0 mm) consumed only power feed. KEYWORDS: Fecundity; Gonadosomatic index (GSI); Yolk absorption; Mouth development; Start of feeding; Starvation, Larviculture; Swamp eel, Monopterus albus

3 Page of Introduction Swamp eel, Monopterus albus is a commercially important fish in Southeast Asia aquaculture industry. To propagate M. albus in commercial-scale hatcheries, it is essential to provide fundamental biology information about the early-life yolk absorption, mouth opening, digestive tract development, and the start of feeding time. Complete yolk absorption is recognized as critical period in larval rearing and survival (Kosutaruk & Watanabe, ; Holm, ; Eda, Fujiwara, & Takita, ; Amornsakun & Hassan, ; Amornsakun, Chiayvareesajja, Hassan, Ambak, & Jee, ; Amornsakun, a; Amornsakun, Sriwatana, & Chamnanwech, 00; Amornsakun, Sriwatana, & Promkaew, 00a; Amornsakun, Sriwatana, & Promkaew, 00b). Survival of fish larvae is determined by the interaction of various environmental factors, such as temperature, food supply with a suite of species-specific characteristics, egg and larval size, yolk and oil globule volume, and its resorption rates, time of onset of feeding and feeding behaviour. Larvae use yolk energy for various activities (Blaxter, ; May, ). Mouth size at first feeding stage of various larval fish encounter their appropriate prey size has been well documented for a number of cultured fish (Shirota, 0; Nash, Kuo, & McConnel, ; Fukuhara, ; Doi&Singhagraiwan, ; Eda, Fujiwara, & Takita, ). M. albus is eel-like shape, with yellow ventral and black dorsal body without pectoral fins (Collin, Trexler, Nico, & Rawlings, 00; Jewham, 00; Jesoa & Kuanmuang, ). M. albus is carnivorous fish that eat shrimp, fish, insect, worm and detritus (Hill & Watson, 00), for example fish (%), shrimp (%) and insect (%) (Shafland, Gestring, & Sanford, 00). Maturity age of the fish is over year old, but can be different between male and female fish (Liem, ). Sexual dimorphism of this fish can only be classified by gonad observation. Sexually-matured female M. albus are known to be about -0 cm long

4 Page of and 00-0 g body weight while the male being 0-. cm long, and g body weight (Kuanmuang, ). Spawners were daily fed with fresh fish, about % of the body weight. Fish spawner will make the fish nest before spawning. Cultured M. albus larvae were fed by commercial pellet known as power feed (containing 0% protein) (Pechcharoon & Uraipradit, 00). However, fundamental information about biological development of early life and female maturation still remain to be discovered therefore this study was designed to investigate baseline information for optimization of large scale culture, and ultimately for the culture management of this fish, including fecundity, gonadosomatic index (GSI) of mature female fish, period of yolk absorption, larvae mouth development, and onset of larvae first feeding period.. Materials and methods The sexual maturity of M. albus was studied by determining its fecundity, egg diameter, and GSI. Fecundity was estimated by a gravimetric method (Tarnchalanukit, Chuapoehuk, Suraniranat, & Na Nakorn, ). Egg diameter was measured using an ocular microscope (Amornsakun, Sriwatana, & Promkaew, 0). GSI was calculated, using the following equation (Tarnchalanukit, Chuapoehuk, Suraniranat, & Na Nakorn, ): GSI= Weight of ovary Weight of body 00 Semi-control natural method was used to produce newly-hatched larvae which were done sexually mature fishes, male and female brooders at a : ratio, were cultured in concrete ponds in which soil was filled as spawning ground and the water depth were kept at 0 cm. The spawners were fed every two days with fresh fish (% of their BW). Fertilized eggs were routinely checked in concrete ponds for daily spawning examination, and transfer fertilized egg to fiberglass tank for hatching.

5 Page of Yolk absorption The time of yolk absorption and the size of yolk-sacs were assessed using a profile projector. Ten newly-hatched larvae were randomly sampled every hours from aquarium until the yolk sacs were fully absorbed. The specimens were fixed in 0% buffered formalin. Yolk volumes were calculated using the following formula (Fukuhara, ): = ( ) where R = minor axis and R = major axis.. Mouth height Samples of twenty newly hatched larvae were taken every hours from the aquarium to measure the size of mouth opening and upper jaw length using a profile projector, after fixing in 0% buffered formalin. The mouth height was calculated as follows (Shirota, 0): mouth height=upper jaw length. Start of feeding Larvae (n=00, aged. days) were fed with Moina (0 µm width) at a density of 0 individual/ml in a -liter aquaria (0 L of water). Twenty larvae were randomly sampled every hours, fixed in 0% buffered formalin and dissected to observe the presence of Moina in the digestive tract which signaled the time of feeding start (Pechmanee, Pongmaneerat, & Iizawa, ). This observation conducted in replication.. Starvation Newly-hatched larvae (00) were starved in a -liter aquaria (0 L of water) to monitor mortalities at every hours till completion in replication (Fukuhara, ).

6 Page of Feed and feeding Larvae (00, aged days) were cultured in a -liter aquaria (0 L of water) and were fed in a scheme, as follows: those aged - days with Moina at a density of 0 individual/ml and those aged - days with Moina and commercial pellet (0% crude protein) (in density :) twice a day (Tarnchalanukit, Chuapoehuk, Suraniranat, & Na Nakorn, ; Kungvankij, Pudadera, Tiro, & Potestas, ; Eda, Darwisito, Fujiwara, & Takita, ). Twenty larvae were randomly and daily collected hour after feeding, fixed in 0% buffered formalin and observed their stomach contents.. Results Female of M. albus (Figure ) were found matured at sized 00-0 g BW, maximum fecundity of 0 ova/fish with GSI.0% (Figure ) in June and minimum fecundity of ova/fish) with GSI of 0.% in October were obtained. The eggs were non-adhesive demersal and rounded with sizes at, µm. The egg were able to classified into groups such as 0-0 µm (.%), -,0 µm (.%),,-,0 µm (.%),,-,0 µm (.0%),,-,0 µm (.%),,-,0 µm (%), and,-,0 µm (%) (Figure ). Newly-hatched larvae (mean±sd, n=0) were.±0.0 cm in length with yolk sacs volume of,.±0.0 µm (Figure ). The yolk sacs were completely absorbed within hah (.±0. cm) at -0. C (Figure ). Mouths were opened about 0 hah (.0±0. cm) with mouth sized at.00±0. µm in width (Figure ), with a straight digestive tract at was.00±0. µm in total length and anus opening at hah (.±0.0 cm) at.0-. C. The average number of Moina in the digestive tract at the start of feeding was 0. individual/larval. The larvae started to feed with Moina at hours

7 Page of after mouth opening, and at hours before yolk absorption. The starved larvae started to die at 0 till,0 hours (. days) (Figure ),.0-0. C. Based on the feeding scheme number of Moina being consumed by -, -, -, -, -, 0-, -, -, -, - and -days-old larvae (.-.0 cm in length) were.,.,., 0.,.,.,.,.,.,. and. individuals/larva, respectively, at -0. C. The larvae at age - days (average total length.-.0 cm) consumed both Moina and commercial pellet. Larvae age more than after -day old (average total length.0 mm) consumed exclusively on power feed.. Discussion The fecundity of M. albus, 0 ova/fish, was comparatively less than those of Channa striatus, Anabas testudineus and Trichogaster pectoralis. But the sexually-matured female M. albus was 00-0 g. Sexually-matured female C. striatus was reported. cm in total length,. g BW, and 0, ova/fish fecundity (Amornsakun, Sriwatana, & Promkaew, 0); whereas A. testudineus being. cm in length and g BW and,0 ova/fish fecundity (Amornsakun, Sriwatana, & Promkaew, 00a) and T. pectoralis being.0 cm in length,.0 g BW,, ova/fish fecundity (Amornsakun, Sriwatana, & Promkaew, 00b). The fertilized eggs of M. albus (, µm in diameter) were classified as large, similar to Mystus wyckioides (,.0 µm), but - times larger than those of C. striatus, A. testudineus and T. pectoralis, respectively (Amornsakun, b; Amornsakun, Sriwatana, & Promkaew, 00a; Amornsakun, Sriwatana, & Promkaew, 00b; Amornsakun, Sriwatana, & Promkaew, 0). The lower GSI of the mature female M. albus of.0% than the normal range -0% of Clarias batrachus (Tarnchalanukit, Chuapoehuk, Suraniranat, & Na Nakorn, ) but similar to C. striatus.0% (Amornsakun, Sriwatana, & Promkaew, 0), and. and. times less than those of A. testudineus and T. pectoralis, respectively (Amornsakun, Sriwatana, & Promkaew, 00a; Amornsakun, Sriwatana, & Promkaew, 00b).

8 Page 0 of The yolk absorption period for newly-hatched larval M. albus was. days after hatching, which were longer than M. nemurus ( days) (Amornsakun, Chiayvareesajja, Hassan, Ambak, & Jee, ), M. wyckioides (. days) (Amornsakun, b) Oxyeleotris marmoratus (. days) (Amornsakun, Sriwatana, & Chamnanwech, 00) A. testudineus (. days) (Amornsakun, Sriwatana, & Promkaew, 00a), T. pectoralis (. days) (Amornsakun, Sriwatana, & Promkaew, 00b), C. striatus (. days) (Amornsakun, Sriwatana, & Promkaew, 0), Mugil curema (. days) (Houde, Berkeley, Klinovsky, & Schekter, ), Chanos chanos (. days) (Chaudhuri, Juario, Primavera, Samson, & Mateo, ) and Clarias sp. (- days) (Tarnchalanukit, Chuapoehuk, Suraniranat, & Na Nakorn, ). The yolk sac volume at the time of the first feeding of M. albus was. %, which were higher C. striatus (.%) (Amornsakun, Sriwatana, & Promkaew, 0), O. marmoratus (.%) (Amornsakun, Sriwatana, & Chamnanwech, 00), similar with M. wyckioides (.0%) (Amornsakun, c), but less than M. nemurus (.0%) (Amornsakun, Chiayvareesajja, Hassan, Ambak, & Jee, ), T. pectoralis (.%) (Amornsakun, Sriwatana, & Promkaew, 00b) and A. testudineus (.0%) (Amornsakun, Sriwatana, & Promkaew, 00a; Kjorsvik, Meerent, Kryvi, Arnfinnson, & Kvenseth, ). The size of Moina was.% of mouth opening of the larval M. albus (.00 µm), in the range 0-0% of mouth size in various fishes (Hunter, 0; Amornsakun, Chiayvareesajja, Hassan, Ambak, & Jee, ; Amornsakun, c; Amornsakun, Sriwatana, & Chamnanwech, 00; Amornsakun, Sriwatana, & Promkaew, 00a; Amornsakun, Sriwatana, & Promkaew, 00b) but different from C. striatus (.%) (Amornsakun, Chiayvareesajja, Hassan, Ambak, & Jee, ; Amornsakun, c; Amornsakun, Sriwatana, & Promkaew, 0) M. wyckioides (.%), M. nemurus (0.%), O. marmoratus (.0%), T. pectoralis (.%) A. testudineus (0.%)

9 Page of (Amornsakun, Sriwatana, & Chamnanwech, 00; Amornsakun, Sriwatana, & Promkaew, 00a; Amornsakun, Sriwatana, & Promkaew, 00b). Moina could be a good live food for larval M. albus because of its suitable size and ease of culture. The number of Moina in the digestive tract at the start of feeding was 0. individual /larva, similar to those reported in T. pectoralis, O. marmoratus and C. striatus, but less than reported in A. testudineus, M. nemurus, M. wyckioides and C. chanos. Gut contents showed 0. rotifer/larva of T. pectoralis (Amornsakun, Sriwatana, & Promkaew, 00b), 0. rotifer/larva of O. marmoratus (Amornsakun, Sriwatana, & Chamnanwech, 00), 0. Moina/ larva of C. striatus (Amornsakun, Sriwatana, & Promkaew, 0),. rotifer/larva of climbing perch (Amornsakun, Sriwatana, & Promkaew, 00a),. individual/larva of green catfish (Amornsakun, Chiayvareesajja, Hassan, Ambak, & Jee, ). Moina/larva of M. wyckioides (Amornsakun, c) and - rotifer /larva of C. chanos (Eda et al., 0). The starved larva of M. albus become debilitated and eventually died at 0 hah, less tolerance lower than A. testudineus ( hours) at.0-0.ºc (Amornsakun, Sriwatana, & Promkaew, 00a), and C. striatus ( hours) at.0-0.ºc (Amornsakun, Sriwatana, & Promkaew, 0). Larvae can tolerate feeding delay up to a certain point depending on the amount of yolk, temperature and other species-specific characteristics (May, ; Hunter, 0; Holm,), for example, days for Engraulis mordax (Lasker, Feder, Theilacker, & May, 0), days for Mugil cephalus (Kuo, Shehadeh, & Milisen, ), days for C. chanos (Chaudhuri, Juario, Primavera, Samson, & Mateo, ), days for Repomucenus sp. (Eda, Darwisito, Fujiwara, & Takita, ), days for Lates calcarifer (Hassan & Amornsakun, ), days for T. pectoralis (Amornsakun et al., 00b). Ishibashi () observed that the yolk sac of unfed Tilapia sparmanii larvae was absorbed faster than that of fed larvae.

10 Page of Food supply during the larval stage is an important factor in achieving high survival and growth rates. Mass mortality of larval and juvenile fish will often occur if the food supply is inadequate (Houde, ). Different species require different sequential food during the early life stages. Most freshwater fish are given rotifer or Moina as a first feeding (Tarnchalanukit, Chuapoehuk, Suraniranat, & Na Nakorn, ; Tawaratmanikul, Viputanimat, Mewan, & Pokasap, ; Vatcharakornyothin, Viputhanumas, Tawaratmanikul, & Pokasap, ), and artificial feeds for juveniles are generally in the form of fine crumbles of appropriate particle size. The larval M. albus is no exception. The type of feed for larval M. albus cultured such as Moina and commercial pellet is similar with other fishes, but time for feeding may be different. It was found that larval M. albus of age - days (average total length.-.0 cm) consumed Moina. The larvae of age - days (average total length.-.0 cm) consumed both Moina and power feed. Larvae aged more than days able to consume completely with power feed. Watanabe, Kitajima, and Fujita () described the food regimes used most extensively in the larvae of various fish production in Japan. In newly hatched fish greater than. mm of body length, rotifers were exclusively given as an initial feed, when fish reached mm or more, marine copepods such as Tigriopus, Acartia, Oithona and Paracalanus were given. Brine shrimp, Artemia salina, were commonly used for the larvae of many species during shortages of marine copepods. Larvae larger than 0 to mm were fed minced fish, shellfish and shrimp or an artificial diet. Tsukashima and Kitajima () reported the rearing of larval and juvenile filefish, Stephanolepis cirrhifer, up to the stage of young fish. They were fed rotifer, Tigriopus japonicus, Artemia and subsequently fish meat. Tarnchalanukit, Chuapoehuk, Suraniranat, and Na Nakorn () reported that C. batrachus of age - days were fed on Moina, and fed with a commercial catfish pellet when they reached 0 days-old. Chawpaknam, Vorasayan, and Poungin (0) reported that fry nursing of two-spot glass

11 Page of catfish, Ompok bimaculatus, of age - days fed with Moina showed a better growth and higher survival rates than those fed with egg custard. The M. albus larvae of age - days (average total length.-.0 cm) consumed zooplankton such as Moina. At days old of larvae consumed only power feed, and this stage is sheer regarded as juvenile stage. The time for juvenile-stage development was similar with the M. nemurus and A. testudineus, but it was earlier than O. marmoratus and T. pectoralis. As reported previously, larval stage for M. nemurus, and A. testudineus were reported at age between -0 and - day-old fed on rotifer and Moina as main diet. At age of day-old onward, both species were developed as juvenile stage and able to fed on commercial artificial (Amornsakun, Chiayvareesajja, Hassan, Ambak, & Jee, ; Amornsakun, Hassan, Ambak, & Chiayvareesajja, ; Amornsakun, Sriwatana, & Promkaew, 00a). While, O. marmoratus have longer larval period at about - days which was only fed on rotifer and Artemia, before reach juvenile stage at 0- day-old fed with either Moina or grinded fish (Amornsakun, Sriwatana, & Chamnanwech, 00a; Amornsakun, Sriwatana, & Chamnanwech, 00b). Despites, T. pectoralis larval stage was reported at the age of - day-old. The first diet T. pectoralis was rotifer at early stage fllowed by Moina. Nevertheless, at age of -0 day-old was able to feed with articicial diet (Amornsakun, Sriwatana, & Promkaew, 00b). We concluded that the size at sexual maturity of female M. albus was 00-0 g in body weight. The eggs were non adhesive demersal and rounded type. Fecundity was maximum (0 ova/fish) in June with GSI of.0 %. The average diameter of egg was, µm. The newly hatched larvae were.±0.0 cm in total length, and had yolk sacs of,.±0.0 µm in volume. The yolk sacs were completely absorbed within hours after hatching at a water temperature of -0. C. All the larvae had open mouths about 0 hours after hatching (.0±0. mm), with mouth size at.00±0. µm opened at

12 Page of hah. The average number of Moina in the digestive tract at the start of feeding was 0. individual/larva. The feed deficit larvae started to die at 0 hours. The feeding scheme of larval M. albus were as follows: larvae of age - days (average total length.-.0 cm) consumed Moina., but at of age - days (average total length.-.0 cm) larvae were able to fed with Moina and commercial pellet know as power feed. Acknowlegements I am grateful to the Prince of Songkla University (ก00) for financial support of the field work. I also thank Mr.Humdee Doloa and MissVeeranut Kuntiyapiruk for assistance in research. And I would also like to thank Assoc. Prof. Dr. Buhri bin Arifin and Assoc. Prof. Dr. Aroonsri Priprem for editorial assistance in preparing this manuscript. References Amornsakun, T. (a). Feeding biology in early life stages of green catfish, Mystus nemurus (Cuv.&Val.). Ph.D. Thesis, Faculty of Applied Science and Technology, University Putra Malaysia Terengganu. p. Amornsakun, T. (b). Preliminary propagation and larval rearing of red-tail catfish, Mystus wyckioides. Research report, Faculty of Science and Technology, Prince of Songkla University, Pattani Campus. p. (in Thai with English abstract) Amornsakun, T. (c). Some aspects in early life stages of larval red-tail catfish, Mystus wyckioides. Songklanakarin Journal of Science and Technology, (), 0-0. Amornsakun, T., & Hassan, A. (). Aspect in early life stage of larval red snapper, Lutjanus argentimaculatus (Forskal). Songklanakarin Journal of Science and Technology, (), -.

13 Page of Amornsakun, T., Sriwatana, W., & Chamnanwech, U. (00). Some aspects in early life stage of sand goby, Oxyeleotris marmoratus. Songklanakarin Journal of Science and Technology, (), -. Amornsakun, T., Sriwatana, W., & Chamnanwech, U. (00a). The culture of sand goby, Oxyeleotris marmoratus I: Feed and feeding scheme of larvae and juveniles. Songklanakarin Journal of Science and Technology, (), -. Amornsakun, T., Sriwatana, W., & Chamnanwech, U. (00b). The culture of sand goby, Oxyeleotris marmoratus II: Gastric emptying times and feed reguirements of larvae. Songklanakarin Journal of Science and Technology, (), -. Amornsakun, T., Sriwatana, W., & Promkaew, P. (00a). Biological breeding and rearing of climbing perch, Anabas testudineus larvae. Research report, Faculty of Science and Technology, Prince of Songkla University, Pattani Campus. p. (in Thai with English abstract) Amornsakun, T., Sriwatana, W., & Promkaew, P. (00b). Some aspects in early life stage of Siamese gourami, Trichogaster pectoralis (Regan) larvae. Songklanakarin Journal of Science and Technology, (), -. Amornsakun, T., Sriwatana, W., & Promkaew, P. (0). Some aspects in early life stage of snake head fish, Channa striatus larvae. Songklanakarin Journal of Science and Technology, (), -. Amornsakun, T., Hassan, A., Ambak, A., & Chiayvareesajja, S. (). The culture of green catfish, Mystus nemurus (Cuv.&Val.) II: Gastric emptying times and feed requirements of larvae fed with Moina. Songklanakarin Journal of Science and Technology, 0(), -. Amornsakun, T., Chiayvareesajja, S., Hassan, A., Ambak, A., & Jee, A. K. (). Yolk absorption and start of feeding of larval green catfish, Mystus nemurus

14 Page of (Cuv.&Val.). Songklanakarin Journal of Science and Technology, (), -. Arul, V. (). Effects of delayed feeding on growth of Channa striatus (Bloch) larvae. Aquaculture Research, (), -. Arumugum, P. T., &Geddes, M. C. (). Feeding and growth of golden perch larvae and fry, Macquaria ambigua Richardson. Transactions of the Royal Society of South Australia, (), -. Bagarinao, T. (). Yolk resorption, onset of feeding and survival potential of larvae of three tropical marine fish species reared in the hatchery. Marine Biology,, -. Blaxter, J. H. S(ed). (). The early life history of fish. New York: Springer-Verlag. p. Chaudhuri, H., Juario, J. V., Primavera, J. H., Samson, R., & Mateo, R. (). Observations on artificial fertilization of eggs and the embryonic and larval development of milkfish, Chanos chanos (Forskal). Aquaculture,, -. Chawpaknam, C., Vorasayan, P., & Poungin, S. (0). Fry nursing of two-spot glass catfish, Ompok bimaculatus. Technical Paper No. /0, Thailand: Chonburi Inland Fisheries Station, Inland Fisheries Division, Department of Fisheries, Ministry of Agriculture and Cooperatives, p. (in Thai with English abstract) Collins, T. M., Trexler, J. C., Nico, L. G., & Rawlings, T. A. (00). Genetic diversity in a morphologically conservative invasive taxon: Multiple introductions of MAs to the southeastern United States. Conservation Biology,, 0-0. Doi, M., & Singhagraiwan, T. (). Biology and culture of the red snapper, Lutjanus argentimaculatus. Thailand: The research project of fisheries resource development in the Kingdom of Thailand, Department of Fisheries. p.

15 Page of Eda, H., Fujiwara, T., & Takita, T. (). Embryonic, larval and juvenile development in laboratory-reared dragonets, Repomucenus beniteguri. Japanese Journal of Ichthyology, 0(), -. Eda, H., Darwisito, S., Fujiwara, T., & Takita, T. (). Rearing of larval and juvenile dragonets, Repomucenus spp. Suisanzoshoku, (), -. Eda, H., Murashige, R., Eastham, B., Wallace, L., Bass, P., Tamaru, C. S., & Lee, C. S. (0). Survival and growth of milkfish, Chanos chanos larvae in the hatchery. I. feeding. Aquaculture,, -. Fukuhara, O. (). Morphological and functional development of Japanese flounder in early life stage. Bulletin of the Japanese Society of Scientific Fisheries, (), -. Fukuhara, O. (). Larval development and behavior in early life stages of black sea bream reared in the laboratory. Nippon Suisan Gakkaishi, (), -. Guma, S. A. (). The food and feeding habits of young perch, Perca fluviatilis, in Windermere. Freshwater Biology,, -. Hassan, A., & Amornsakun, T. (). The influences of initial delay of feeding on survival and growth of the seabass, Lates calcarifer. In the Annual Meeting of the World Aquaculture Society (January - February, ), Queen Sirikit National Convention Center, Bangkok, Thailand, p.. Hill, J. E., & Watson, C. A. (00). Diet of the nonindigenous Monopterus albus in tropical ornamental aquaculture ponds in West-Central Florida. North American Journal of Aquaculture,,. Hodson, P. V., & Blunt, B. R. (). The effect of time from hatch on the yolk conversion efficiency of rainbow trout, Salmo gairdneri. Journal of Fish Biology,, -. Holm, J. C. (). Yolk sac absorption and early food selection in Atlantic salmon feeding on live prey. Aquaculture,, -.

16 Page of Houde, E. D. (). Effects of temperature and delayed feeding on growth and survival of larvae of three species of subtropical marine fishes. Marine Biology,, -. Houde, E. D. (). Critical food concentrations for larvae of three species of subtropical marine fishes. Bulletin of Marine Science, (), -. Houde, E. D., Berkeley, S. A., Klinovsky, J. J., & Schekter, R. C. (). Culture of larvae the white mullet, Mugil curema Valenciennes. Aquaculture,, -0. Hunter, J. R. (0). The feeding and ecology of marine fish larvae. In Bardach, J. E., Magnuson, J. J., May, R. C. and Reinhart, J. M. (Editors) Fish Behaviour and Its Use in Capture and Culture of Fishes. ICLARM Conf. Proc., Manila, Philippine, pp. -0. Hyatt, K. D. (). Feeding strategy. In Hoar, W. S., Randall, D. J. and Brett, J. R. (eds) Fish Physiology, Vol. VIII. London: Academic Press. pp. -. Ishibashi, N. (). Feeding, starvation and weight changes of early fish larvae. In Blaxter, J. H. S. (ed) The Early Life History of Fish. New York: Springer-Verlag. pp. -. Ito, T., & Suzuki, R. (). Feeding habits of a cyprinid loach in the early stages. Bullatin Freshwater Research Laboratory,, -. Jewham, V. (00). Reproductive biology and principle of Monopterus albus breeding (Monopterus albus Zuiew) in concrete pond by natural method. Research Journal, (), -. (in Thai with English abstract) Jesoa, S., & Kuanmuang, S. (). Biology and Commercial Culture of Monopterus albus (Monopterus albus Zuiew). Technical Paper No. /, Thailand: Pattani Inland Fisheries Research and Development Center, Department of Fisheries, Ministry of Agriculture and Co-operatives, 0 p. (in Thai with English abstract)

17 Page of Juario, J. V., Duray, M. N., Nacario, J. F., & Almendras, J. M. E. (). Breeding and larvae rearing of the rabbitfish, Siganus guttatus (Bloch). Aquaculture,, -0. Kjorsvik, E., Meerent, T., Kryvi, H., Arnfinnson, J., & Kvenseth, P. G. (). Early development of the digestive tract of cod larvae, Gadus morhua L., during start-feeding and starvation. Journal of Fish Biology,, -. Kosutaruk, P., & Watanabe, T. (). Growth and survival of newly hatched larvae of seabass, Lates calcarifer in starved condition. Report of Thailand and Japan Joint Coastal Aquaculture Research Project (April -March ) No., September. Thailand: National Institute of Coastal Aquaculture. pp. -. Kuanmuang, S. (). Preliminary study some biology and experiment on Monopterus Albus (Monopterus albus Zuiew) breeding. Thailand Fisheries Magazine, () -0. (in Thai with English abstract) Kungvankij, P., Pudadera, B. J. Jr., Tiro, L. B. Jr., & Potestas, I. O. (). Biology and Culture of Seabass, Lates calcarifer. Thailand: Network of Aquaculture Centre in Asia, p. Kuo, C. M., Shehadeh, Z. H., & Milisen, K. K. (). A preliminary report on the development, growth and survival of laboratory reared larvae of the grey mullet, Mugil cephalus L. Journal of Fish Biology,, -0. Lasker, R., Feder., H. M., Theilacker, C. H., & May, R. C. (0). Feeding, growth and survival of Engraulis mordax larvae reared in the laboratory. Marine Biology,, -. Liem, K. F. (). Sex reversal as a natural process, Monopterus albus. American Society of Ichthyologists and Herpetogists, (), 0-. Maneewong, S., Akkayanont, P., Pongmaneerat, J., & Iizawa, M. (). Larval rearing and development of grouper, Epinephelus malabaricus

18 Page 0 of (Bloch and Schneider). Report of Thailand and Japan Join Coastal Aquaculture Research Project (April -January ) No., April. Thailand: National Institute of Coastal Aquaculture, pp. -. May, R. C. (). Larval mortality in marine fishes and the critical period concept. In Blaxter, J. H. S. (ed.) The Early Life History of Fish. New York: Springer-Verlag, pp. -. Nash, C. E., Kuo, C. M., & McConnel, S. C. (). Operational procedures for rearing larvae of the grey mullet, Mugil cephalus Linnaeus. Aquaculture,, -. Pechcharoon, P., & Uraipradit, K. (00). Influence on growth with different stocking of Monopterus albus (Monopterus albus Zuiew) culture. Technical Paper No. /00, Thailand: Pattani Inland Fisheries Research and Development Center, Department of Fisheries, Ministry of Agriculture and Co-operatives, p. (in Thai with English abstract) Pechmanee, T., Pongmaneerat, J., & Iizawa, M. (). Effect of food density on food comsumption for larval seabass, Lates calcarifer. In Report of Thailand and Japan Join Coastal Aquaculture Research Project (April - January ) No., April. Thailand: National Institute of Coastal Aquaculture, pp. -. Shafland, P. L., Gestring, K. B., & Sanford, M. S. (00). An assessment of the Asian MA (Monopterus albus) in Florida. Reviews in Fisheries Science, (), -. Shirota, A. (0). Studies on the mouth size of fish larvae. Bulletin of the Japanese Society of Scientific Fisheries, (), -. (in Japanese with English abstract) Tarnchalanukit, W., Chuapoehuk, W., Suraniranat, P., & Na Nakorn, U. (). Pla Duk Dan Culture. Thailand: Faculty of Fisheries, Kasetsart University. pp. (in Thai)

19 Page of Tawaratmanikul, P., Viputanimat, T., Mewan, A., & Pokasap, K. (). Study on the Suitable Moina Density in Nursing the Giant Catfish, Pangasianodon gigas. Technical Paper No. /, Thailand: Pathumthani Freshwater Fisheries Station, Inland Fisheries Division, Department of Fisheries, Ministry of Agriculture and Cooperatives, p. (in Thai with English abstract) Tsukashima, T., & Kitajima, C. (). Rearing and development of larval and juvenile filefish, Stephanolepis cirrhifer. Bullatin Nagasaki Prefectural Institute of Fisheries,, -. (in Japanese with abstract in English) Vatcharakornyothin, V., Viputhanumas, T., Tawaratmanikul, P., & Pokasap, K. (). The Suitable Moina Density in Nursing the Different Species of Catfish Fries. Technical Paper No. /, Thailand: Pathumthani Freshwater Fisheries Station, Inland Fisheries Division, Department of Fisheries, Ministry of Agriculture and Co-operatives, p. (in Thai with English abstract) Ware, D. M. (). Relation between egg size, growth and natural mortality of larval fish. Journal of the Fisheries Research Board of Canada,, 0-. Watanabe, T., Kitajima, C., & Fujita, S. (). Nutritional values of live organisms used in Japan for mass propagation of fish : Review. Aquaculture,, -.

20 Page of Figure. Matured female of swamp eel

21 Page of Figure. The ovary of swamp eel

22 Page of Figure. The Eggs of swamp eel

23 Page of Figure. Newly hatched larvae of swamp eel

24 Page of Yolk Volume (cubic micrometer) Time Elasped from Hatching (hr) Figure. Total length (TL) and yolk absorption of larval swamp eel at elapsed time after hatching YV: Yolk volume

25 Page of Mouth Height (micron) Time Elasped from Hatching (hr) Figure. Total length (TL) and development of mouth opening of larval swamp eel at elapsed time after hatching MO: Mouth Opening 0

26 Page of Survival Rate (%) Time Elasped from Hatching (hr) Figure. Survival of swamp eel after hatching without feeding at.0 to 0. C