Artificial fertilization of the eggs, and rearing and identification of the larvae of the anchoveta, Cetengraulis mysticetus

ENGLISH: The anchoveta, Cetengraulis mysticetus (Günther), is an important bait fish used to capture tunas in the Eastern Tropical Pacific Ocean. Contributions to the early life history of this species in the Gulf of Panama were made by Simpson (1959), who was able to identify deductively the planktonic egg of the anchoveta from 10 other anchovy eggs concurrently present. He also reared these planktonic eggs in the laboratory and described the resultant larvae to the age of 48 hours after hatching. Because of the lack of differences among the anchovy larvae, this description does not permit the identification of anchoveta larvae from those of other engraulid species. Furthermore, while adult specimens are easily recognized, up to the present it has not been possible to extend the identification of the juvenile anchoveta to specimens smaller than about 25 mm. The purpose of this study, therefore, was to identify anchoveta from the time of hatching to about 25 mm. SPANISH: La anchoveta, Cetengraulis mysticetus (Günther), es un importante pez de carnada que se emplea en la captura de los atunes en el Océano Pacífico Oriental Tropical. Simpson (1959) logró identificar deductivamente el huevo planctónico de la anchoveta al separarlo de otros diez huevos de anchoas que se encuentran al mismo tiempo, contribuyendo de esta manera a conocer los primeros estados de la historia natural de esta especie en el Golfo de Panamá. El también estableció un criadero en el laboratorio con estos huevos planctónicos y describió las larvas resultantes hasta la edad de 48 horas después de la eclosión. Debido a que no hay diferencias entre las larvas de las anchoas, esta descripción no permite identificar las larvas de la anchoveta de las otras especies de engráulidos. Más aun, a pesar de que los especímenes adultos son fácilmente reconocibles, hasta ahora no ha sido posible identificar la anchoveta juvenil de menos de unos 25 mm. Consecuentemente, el propósito del presente estudio ha sido el de identificar al anchoveta desde el momento de la eclosión hasta que tiene unos 25 mm.

Breeding biology and monosex male seed production of Genetically Improved Farmed Tilapia (GIFT) strain of Oreochromis niloticus L. in Bangladesh

A study on the breeding biology of the GIFT strain of Nile tilapia, Oreochromis niloticus, was conducted for a period of five months. The sex ratio of the parent individuals was optimized for performance in spawn production, where the best results were obtained with a sex ratio of female to male of 4:1 compared to those of 3:1 and 2:1. The diameter of eggs obtained from the GIFT stock had major and minor axes of 2.19±0.09 and 1.72±0.07 mm, respectively, with no significant differences between the treatments. The average number of eggs produced was 392±22 per female, with fertilization and hatching rates ranging between 94-96% and 85-88%, respectively. No significant variation was observed between the treatments. Breeding frequencies per female in the three treatment groups ranged between 10-40 days and the highest value was obtained at a female to male sex ratio of 4: l. In an other experiment, l7 aMethyltestosterone (MT) was applied orally to the fry at their first feeding stage with treatments- 1, 2, 3 and 4 at the dosage of 100, 80, 60 and 40 mg/kg feed respectively, for the period of 28 days. The mean percentage of males obtained in treatments, 1, 2, 3 and 4 were 98, 97, 95 and 68, respectively. Treatments-1, 2 and 3 did not differ significantly (P>0.05) from each other but treatment 4 showed significant variation (P<0.05) from other treatments. The results showed that MT-100, 80 and 60 mg/kg feed administered for 28 days produced close to cent percent male population of the GIFT strains in aquaria.

Observations on the artificial fertilization of eggs and larval rearing of the grey mullet, Mugil cephalus L.

The results are presented of attempts to artificially fertilize Mugil cephalus eggs in the Philippines. Embryonic development is outlined and rearing of the larvae described. Mass mortality occurred during week 3 of rearing.

Reproductive Biology of Amblema neislerii, Elliptoideus sloatianus, Lampsilis subangulata, Medionidus penicillatus, and Pleurobema pyriforme (Bivalvia: Unionidae): final report

A study on the reproductive biology of Amblema neislerii, Elliptoideus sloatianus, Lampsilis subangulata, Medionidus penicillatus, and Pleurobema pyriforme was conducted from May 1995 to May 1997. The objectives of this study were as follows: 1) determine period of gravidity for each of the five mussel species, 2) determine host fish via laboratory experiments, 3) test whether unionid glochidia will transform on a nonidingenous fish, and 4) describe the glochidial morphology for each of the five mussel species using a scanning electron microscope. Amblema neislerii are tachytictic breeders and were found with mature glochidia in May. Elliptoideus sloatianus are tachytictic breeders and were found with mature glochidia from late February to early April. Lampsilis subangulata are bradytictic breeders and were found with mature glochidia from December to August. Superconglutinates were released by L. subangulata from late May to early July. Medionidus penicillatus are bradytictic breeders and were found with mature glochidia in November and February to April. Pleurobema pyriforme are tachytictic breeders and were found with mature glochidia from March to July. The following fish species served as hosts for A. neislerii: Notropis texanus, Lepomis macrochirus, L. microlophus, Micropterus salmoides, and Percina nigrofasciata. The following fish species served as hosts for E. sloatianus: Gambusia holbrooki, Poecilia reticulata, and P. nigrofasciata. The following fish species served as hosts for L. subangulata: G. holbrooki, P. reticulata, L. macrochirus, Micropterus punctulatus, and M. salmoides. The following fish species served as hosts for M. penicillatus: G. holbrooki, P. reticulata, Etheostoma edwini, and P. nigrofasciata. The following fish species served as hosts for P. pyriforme: Pteronotropis hypselopterus, G. holbrooki, and P. reticulata. Poecilia reticulata, a nonindigenous fish, served as a host for E. sloatianus, L. subangulata, M. penicillatus, and P. pyriforme. (76 page document)

Biology and Fishery of Florida's commercial sponges

(PDF has 2 pages.)

The ontogeny of haematopoiesis in the marine teleost Leiostomus xanthurus and a comparison of the site of initial haematopoiesis with Opsanus tau

The ontogeny of haematopoiesis in the perciform fish, spot Leiostomus xanthurus, differed from that reported as the norm for fishes, as exemplified by the cypriniform zebrafish Danio rerio, and observed in the batrachoidiform oyster toadfish Opsanus tau. Erythropoiesis in spot was first evident in the head kidney of yolk-sac larvae 3 days after hatching (DAH). No embryonic intermediate cell mass (ICM) of primitive stem cells or blood islands on the yolk were apparent within embryos. Erythrocytes were first evident in circulation near the completion of yolk absorption, c. 5 DAH, when larvae were c. 20 mm notochord length (LN). Erythrocyte abundance increased rapidly with larval development for c. 14 to 16 DAH, then became highly variable following changes in cardiac chamber morphology and volume. Erythrocytic haemoglobin (Hb) was not detected within whole larvae until they were 12 DAH or c. 31 mm LN, well after yolk and oil-globule absorption. The Hb was not quantified until larvae were >47 DAH or >7 mm standard length. The delayed appearance of erythrocytes and Hb in spot was similar to that reported for other marine fishes with small embryos and larvae. In oyster toadfish, a marine teleost that exhibits large embryos and larvae, the ICM and Hb were first evident in two bilateral slips of erythropoietic tissue in the embryos, c. 5 days after fertilization. Soon thereafter, erythrocytes were evident in the heart, and peripheral and vitelline circulation. Initial haematopoiesis in oyster toadfish conformed with that described for zebrafish. While the genes that code for the development of haematopoiesis are conserved among vertebrates, gene expression lacks phylogenetic pattern among fishes and appears to conform more closely with phenotypic expression related to physiological and ecological influences of overall body size and environmental oxygen availability.

Proceedings of the Nineteenth Annual Symposium on Sea Turtle Conservation and Biology, 2-6 March 1999 South Padre Island, Texas, U.S.A.

The 19th Annual Symposium on Sea Turtle Biology and Conservation was the largest to date. The beautiful venue was the South Padre Island Convention Centre on South Padre Island, Texas from March 2-6, 1999. Key features of the 19th were invited talks on the theme The Promise, the Pain, and the Progress of 50 years of Sea Turtle Research and Conservation, a mini-symposium on the Kemp's ridley and an increased emphasis on high quality poster sessions. Hosts for the meeting included Texas A&M University, the Texas Sea Grant College Program, The Gladys Porter Zoo and Sea Turtle, Inc. Co-sponsors included the National Marine Fisheries Service-Southeast Fisheries Science Center, the National Marine Fisheries Service-Protected Resources Branch, Padre Island National Seashore and the U.S. Fish and Wildlife Service. With the assistance of Jack Frazier, we were fortunate to obtain a $30,000 grant from the David and Lucile Packard Foundation. This grant provided travel support to 49 individuals from 24 nations who presented a total of 50 presentations. (PDF contains 309 pages)

Proceedings of the Twenty-second Annual Symposium on Sea Turtle Biology and Conservation, 4-7 April, 2002, Miami, Florida

The 22nd Annual Symposium on Sea Turtle Biology and Conservation was held April 4-7, 2002 in Miami, Florida and hosted by the U.S. Fish and Wildlife Service. The 22nd symposium was the most globally diverse ever with 839 individuals from 73 countries attending the symposium and associated regional meetings. One third of the attendees were from outside the United States. This diverse attendance was made possible in large part because of substantial donations from The Packard Foundation, National Fish and Wildlife Foundation, National Marine Fisheries Service, U.S. Fish and Wildlife Service, Convention on Migratory Species, Oceanic Research Foundation, and International Sea Turtle Society which supported travel grants for 170 international travelers. (PDF contains 336 pages)

Biology and fisheries of swordfish, Xiphias gladius: Papers from the International Symposium on Pacific Swordfish, Ensenada, Mexico, 11-14 December 1994

The swordfish, Xiphias gladius, is a large migratory oceanic species. It is widely distributed in tropical, temperate, and sometimes cold waters of all oceans, and is usually found in areas with sea-surface temperatures above 13°C. It can reach a maximum size of 540 kg, and is a favorite food fish in many countries. It is excellent for steaks, canning, or teriyaki, the Japanese dish of meat grilled with sugar, soy sauce, and rice wine. Swordfish is harvested commercially throughout its distribution, in both coastal and high-seas fisheries. Sport fisheries for swordfish are very small compared to those for other billfishes, accounting for no more than a few hundred fish per year. (PDF file contains 284 pages.)

Biology and Management of Sablefish, Anoplopoma fimbria: Papers from the International Symposium on the Biology and Management of Sablefish, Seattle, Washington, 13-15 April 1993

At its june 1990 annual meeting, the Technical Subcommittee (TSC) of the Canada-U.S. Groundfish Committee recommended that scientists and managers working on sablefish, Anoplopoma fimbria, issues convene to present and discuss the results of their recent research. Thorough knowledge of the biology and population dynamics of this species is essential for its effective management, especially considering its commercial importance. TSC representatives from both countries recognized that a great deal ofactive research has been conducted on this species since the International Sablefish Symposium was held in Anchorage, Alaska, in March 1983 (Melteff, 1983). As a result of this recommendation, the International Symposium on the Biology and Management of Sablefish (ISBMS) was convened April 13-15, 1993, at the Alaska Fisheries Science Center in Seattle, Washington. (PDF file contains 286 pages.)

Conservation Biology of Elasmobranchs

Elasmobranchs are vital and valuable components of the marine biota. From an ecological perspective they occupy the role of top predators within marine food webs, providing a regulatory control that helps balance the ecosystem. From an evolutionary perspective, this group represents an early divergence along the vertebrate line that produced many unusual, but highly successful, adaptations in function and form. From man's perspective, elasmobranchs have been considered both an unavoidable nuisance, and an exploitable fishery resource. A few of the large shark species have earned a dubious notoriety because of sporadic attacks on humans that occur in coastal areas each year worldwide; the hysteria surrounding an encounter with a shark can be costly to the tourist industry. More importantly, elasmobranchs are often considered a detriment to commercial fishing operations; they cause significant economic damage to catches and fishing gear. On the other hand, consumer attitudes have changed concerning many previously unpopular food fishes, including elasmobranchs, and this group of fishes has been increasingly used by both recreational and commercial fishing interests. Many elasmobranchs have become a popular target of recreational fishermen for food and sport because of their abundance, size, and availability in coastal waters. Similarly, commercial fisheries for elasmobranchs have developed or expanded from an increased demand for elasmobranch food products. (PDF file contains 108 pages.)

Biology, Oceanography, and Fisheries of the North Pacific Transition Zone and Subarctic Frontal Zone: Papers from the North Pacific Transition Zone Workshop, Honolulu, Hawaii, 9-11 May 1988

In the past few years, large-scale, high-seas driftnet fishing has sparked intense debate and political conflict in many oceanic regions. In the Pacific Ocean the driftnet controversy first emerged in the North Pacific transition zone and subarctic frontal zone, where driftnet vessels from Japan, the Republic of Korea, and Taiwan pursue their target species of neon flying squid. Other North Pacific driftnet fleets from Japan and Taiwan target stocks of tunas and billfishes. Both types of driftnet fishing incidentally kill valued non-target species of marine life, including fish, mammals, birds, and turtles. In response to public concerns about driftnet fishing, government scientists began early on to assemble available information and consider what new data were required to assess impacts on North Pacific marine resources and the broader pelagic ecosystem. Accordingly, a workshop was convened at the NMFS Honolulu Laboratory in May 1988 to review current information on the biology, oceanography, and fisheries of the North Pacific transition zone and subarctic frontal zone. The workshop participants, from the United States and Canada, also developed a strategic plan to guide NMFS in developing a program of driftnet fishery research and impact assessment. This volume contains a selection of scientific review papers presented at the 1988 Honolulu workshop. The papers represent part of the small kernel of information available then, prior to the expansion of cooperative international scientific programs. Subsequent driftnet fishery monitoring and research by the United States, Canada, Japan, Korea, and Taiwan have added much new data. Nevertheless, this collection of papers provides a historical perspective and contains useful information not readily available elsewhere. (PDF file contains 118 pages.)

Elasmobranchs as living resources: Advances in the biology, ecology, systematics, and the status of the fisheries

This report owes its genesis to the foresight and enthusiam of Dr. Kazuhiro Mizue. By happy circumstance, Professor Mizue contacted me in 1983 with his visionary ideas on cooperative programs. He noted that the time was right because the Japan Society for the Promotion of Science and the National Science Foundation had mutually given priority to cooperative programs in marine biology. I therefore agreed to act as the U.S. coordinator and proposed to NSF, a short trip to Japan to negotiate site visits and timing with ten previously appointed Japanese scientists and, if that trip were successful, to negotiate a joint research project, possibly followed by a joint seminar. (PDF file contains 528 pages.)