HCG and LHRH-A induced spawning in bighead carp Aristichthys nobilis Rich. reared in floating cages in Laguna de Bay
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Hormone-induction of spawning in bighead carp Aristichthys nobilis Rich. by single or double intraperitoneal injection with varying combined dosages of HCG and LHRH-A was conducted. Fish were spawned successfully following a single or double injection with 1800 to 2000 IU HCG in combination with 10, 15 or 20 µg HRLR-A per kg body weight. Fish injected with lower dosages of HGC at 1200 or 1500 IU/kg body weight plus 20 µg/kg LHRH-A did not differ significantly (P>0.05). Fish given a single injection ovulated after 12.0 ± 0.1 hours. No significant difference was found in the total number of eggs spawned per fish among the injection protocols (P>0.05). However, lower fertilization and hatching rates of eggs were observed in fish that spawned spontaneously in the tank as compared to those fish whose eggs were stripped and dry-fertilized (P<0.05).
CitationFermin, A. C., & Reyes Jr., D. M. (1989). HCG and LHRH-A induced spawning in bighead carp Aristichthys nobilis Rich. reared in floating cages in Laguna de Bay.
PublisherSan Carlos Publications, University of San Carlos
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Fisheries Research Journal of the Philippines, 1986 - Fisheries Research Society of the PhilippinesIncreasing fish production through polyculture was clearly demonstrated to the fishfarmers in Laguna lake. The rearing of different species of fish of proper number and species combinations had resulted to the efficient utilization of all the available food niches/zones in the lake. Fish production is site specific in Laguna lake. Wide variation in growth increment and fish yield were observed among the different bays and among farm sited within a bay. The final mean weights of the fish species were 355 mg to 2300 g for bighead carp, 32 g to 103.3 g for tilapia and 8.3 g to 1800 g for common carp.
ArticleLMB Garcia, CMH Garcia, AFS Pineda, EA Gammad, J Canta, SPD Simon, GV Hilomen-Garcia, AC Gonzal & CB Santiago -
Aquaculture International, 1999 - KluwerBighead carp (Aristichthys nobilis Oshima) fry of various ages (11, 18, and 35 days post-hatch) were exposed to the low salinities encountered during the annual intrusion of seawater in Laguna Lake, Philippines. Practical indices of salinity tolerance assessed the effect of a 96 h direct exposure to low salinities (0–16‰). Mean (MST) and median survival times (MST50) of fry decreased as salinity of rearing medium increased. Younger fry were less able to tolerate exposure to these salinities than their older cohorts. Median lethal salinity after 96 h (MLS) revealed higher tolerance among 35–day old fry (7.6‰) than 11 (2.3‰) and 18–day old fry (6.0‰), demonstrating that survival in saline water depends on their age at initial exposure to low salinities. Mean body weight of 18–day old fry reared in 0 and 2‰ for 3 and 4 weeks was higher than for those reared in 4 and 6‰ for the same period. Growth over these periods was inversely related with the range of salinities tested. These results demonstrate that, despite their known stenohalinity, bighead carp fry possess some degree of osmoregulatory capability, allowing them to survive and grow in lakes subjected periodically to saltwater inflow.
Growth and survival of bighead carp (Aristichthys nobilis) fry fed at different intake levels and feeding frequencies MH Carlos -
Aquaculture, 1988 - ElsevierThis study was conducted to assess the effect of different levels of dietary intake and feeding frequencies on growth and survival of bigheadcarp, Aristichthys nobilis, fry. The feeding rates consisted of 10%, 20%, and 30% of body weight while feeding frequencies were one, three, and five times daily. Results showed that final weight, final length, and specific growth rate (SGR) differed in relation to feeding rate but not to feeding frequency. Highest values were obtained for fish on the 30% ration and fed once a day. A significant effect of higher feeding rate using lower feeding frequency on growth was manifested in final mean weight and SGR; increasing feeding rate resulted in increased growth. Feeding frequency significantly influenced fry survival with highest values observed when fry were fed once or three times per day. Highest survivals were achieved by fry on the 30% ration fed once daily. At higher feeding rates using lesser feeding frequencies better survival was noted. Survival rate had an inverse relationship to feeding frequency, but no overall relationship existed between feeding rate and survival rate. Both ration and feeding frequency significantly influenced normalized biomass index (NBI). Highest values were again obtained on the 30% ration and feeding once daily. Higher NBI values were observed with higher feeding rates at lower feeding frequencies. Increasing ration resulted in a corresponding increase in NBI.