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Broodstock of Atlantic cod were fed with three diets; astaxanthin supplemented (100 ppm kg−1) hydrated diet (30% water) ( HWHAs), no additional astaxanthin supplemented (50 ppm kg−1) hydrated diet (30% water) ( HWLAs) and a control diet (50 ppm kg−1 astaxanthin and 10% water). Throughout the spawning period, eggs were collected daily and fertilization success and proportion of embryos with normal cleavage were recorded. Larvae were reared using standard culture methods. Larval growth was recorded every 10 days and larval survival was recorded at 50 days post hatch. In general, broodstock fed with diets containing higher water content ( HWHAs and HWLAs) and higher astaxanthin ( HWHAs) had higher egg production and efficiency of egg output, lower egg incubation mortality and higher larval growth and survival. Broodstock fed with higher water content diets consumed less feed compared to control group. Also, broodstock fed with HWHAs and HWLAs recovered faster in terms of body condition than the control group. The egg bound mortality of female fish was significantly higher in control broodstock compared to broodstock fed with HWHAs and HWLAs. Broodstock fed with higher astaxanthin ( HWHAs) had significantly higher fertilization success than other two groups however; no differences were found in proportion embryos with normal cleavage among different groups. Larval survival was significantly higher in HWHAs broodstock compared to other two groups. Our results showed that increased water content and astaxanthin levels in the diet could improve the condition and fecundity of Atlantic cod broodstock. [ABSTRACT FROM AUTHOR]

The article presents a report on the formation and management of red scorpionfish broodstock in obtaining spontaneous spawning. It states that the broodstock are formed from captured wild fish adults using specially made nets. The fish eggs and larvae's morphological characteristics and starting live food are also discussed.

This study aimed to elucidate the causes of variability in larval survival and juvenile abundance (recruitment) within and among cohorts of Japanese sea bass (JSB; Lateolabrax japonicus), a winter-spawning temperate coastal marine fish. Larvae and settled individuals (settlers) belonging to four cohorts were collected from Tango Bay (the Sea of Japan coast) during eight sampling cruises in 2007 and 2008. Larvae were sampled in January and February each year using an ichthyoplankton net, and settlers were collected in February and March each year using a beam trawl. Age of individual larva and settlers was determined and growth history was back-calculated from otolith microstructure, and the hatch date distribution was computed. Temperature, daily growth rate, size-at-age, hatch date, and density data of larvae and settlers allowed elucidating the effects of the timing of spawning and larval quantity and quality (growth rate and body size) on larval survival and recruitment within and among cohorts of JSB. Results showed that cohorts that hatched earlier in the season had higher quantity of larvae, experienced higher mean temperatures and survived better than cohorts hatched later. Recruitment variability among cohorts is determined largely by the initial quantity of larvae, as this explained >97% of the variability in recruitment among cohorts. Within cohorts, larger hatched larvae grew faster than their smaller conspecifics, and the bigger and faster growing larvae survived and settled. Results from this study suggest the following scenarios for recruitment of JSB: (i) earlier spawning in the season promotes larval survival since earlier cohorts are likely to encounter a better temperature and perhaps food conditions, and therefore recruit better than later cohorts; (ii) the initial quantity of larvae appears to be an important determinant of recruitment variability among cohorts; and (iii) the size- and growth-related mechanisms operating during the larval phase appear to start at the time of the hatch. [ABSTRACT FROM AUTHOR]

The present study describes the adaptation of longfin yellowtail Seriola rivoliana as broodstock and first larval rearing trials under intensive and semi-intensive conditions. Fifteen sub-adults were captured in the South coast of Gran Canaria (Canary Islands, Spain) in June 2007. Fish (initial weight 1.76 ± 0.25 kg) reached a weight of 6.0 ± 1.1 kg in July 2010. Once a year, fish were sampled to determine individual growth in weight and size. In addition, the state of sexual maturity was established based on gonadal biopsies. On the basis of repeated hormonal injection (Gn RHa, 20 μg/kg), 10 successful spawns were obtained between July and October 2009, with 92.5 ± 5.5% and 72.6 ± 17.2%, fertilization and egg viability respectively. First results of larval rearing under semi-intensive conditions, showed an average survival at 30 DAH of 2.5% as compared with 0.5% under intensive conditions. The low survivals under the two rearing conditions in addition to their failure to pass a stress test could be attributed to deficiencies in essential fatty acids as could be seen in both eggs and feeds. Morphometric parameters showed no significant difference between the two rearing systems in 230 DAH larvae. [ABSTRACT FROM AUTHOR]

The effect of incubation temperature on embryonic development and yolk-sac larva of the Pacific red snapper Lutjanus peru were evaluated by testing the effect of 26, 28 and 30°C, as this is the natural thermal interval reported during the spawning season of Pacific red snapper in the Gulf of California, Mexico. Sixteen developmental stages were observed. The incubation temperature affected the rate of development and time to hatching, being shorter at 30 than at 26°C, but no significant effect ( P < 0.05) on larval length at hatching was registered. The depletion rate of yolk sac and oil globule was affected by incubation temperature particularly during the first 12 h post hatching (hph). At the end of the experiment (48 hph), significantly ( P < 0.05) larger larvae were recorded at 26°C ( TL = 3.22 ± 0.01 mm) than at 28° ( TL = 3.01 ± 0.02 mm) and 30°C ( TL = 2.97 ± 0.05 mm). Incubation of newly fertilized eggs at 26°C produces larger larvae, which may help to improve feeding efficiency and survival during first feeding. [ABSTRACT FROM AUTHOR]

The article presents a study which provides a distributional information and descriptions of larval development in Doederleinia berycoides in the coastal waters of Niigata in the northern Japan Sea. The ontogenic development of D. berycoides such as the appearance of distinctive melanophores on the rostral tip, isthmus, throat is cited. It is inferred that the larvae of the species disperse to a wide extend from near-shore to offshore waters during their pelagic phases.