| Summary: | 博士 === 國立臺灣海洋大學 === 環境生物與漁業科學學系 === 95 === Reproduction, metabolism and bioenergetics of whitespotted bamboo shark in northern Taiwan waters were examined. A total of 491 whitespotted bamboo shark were collected at Fuji fishing port from February 2002 to February 2003. Sex ratio of the specimens was 0.65, total length ranged from 35.3 to 85 cm, mass ranged from 124 to 2580 g. The mean size at maturity was estimated to be 64.9 cm TL and 65.6 cm TL for females and males, respectively based on the relationship between mature percentage and total length. The ovulation season was estimated from March to May and mating season was from December to January. The inconsistence of mating and ovulation seasons suggested that females have sperm storage and delayed fertilization. Six gravid sharks were captive in the tanks to observe the spawning cycle and number of eggs deposited. One or two eggs were deposited every 6 or 7 days on average. Deposition of eggs extended for 2 months, and fecundity was 8±3.8 eggs. The hatching period was 107±9.3 days with accumulated water temperature ranging from 2372 ºC to 2835 ºC.
There was a significant relationship between specific growth rate and mean daily ration of new hatching sharks, SGR = 2.7822*Ration – 5.1056 (n = 18, r2 = 0.54, P < 0.05). Mean standard metabolic rates (SMR) of juvenile whitespotted bamboo sharks were 16.58 ± 2.81 mg O2 h-1 at 18 ºC and 38.60 ± 7.32 mg O2 h-1 at 28 ºC, respectively. The mean Q10 ± SD for 18 ºC to 28 ºC was estimated to be 2.32 ± 0.06. No significant differences between sexes in SMR and Q10 were found (P > 0.05). The amount of oxygen consumed per hour changed predictably with body size according to the relationship (n = 40, r2 = 0.92, P < 0.05). The mean specific dynamic action (SDA) magnitude was 95.28 ± 17.55 mg O2 kg-1 h-1. The duration of the SDA effect was 122 h.
Energy contents of body tissue, gonad of whitespotted bamboo shark, squid, and feces determined by bomb calorimeter were 5.67 kJ g wet w-1, 10.44 kJ g wet w-1, 3.75 kJ g wet w-1, and 2.09 kJ g wet w-1, respectively. An average bioenergetics budget for juvenile whitespotted bamboo shark fed with squid at 18 ºC was 100C = 29.5G + 31.9SMR + 28.2SDA + 6.7F + 2.1E + 1.6U. The bioenergetics budget for adult whitespotted bamboo shark was 100C = -1.2G + 27.8SMR + 28.2SDA + 6.7F + 2.1E + 36.5S - 0.1U in spawning season. After a period of 365 days simulation, population number decreased from 10000 to 7199. Total consumptions of squid per year for juveniles and adults were 17,087 kg and 28,363 kg, respectively.
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