Effects of salinity, aeration and light intensity on oil globule absorption, feeding incidence, growth and survival of early-stage grouper Epinephelus coioides larvae     

Joebert Delfin  TOLEDO  Nora Blanca  CABEROY  Gerald Fontelera  QUINITIO  Casiano Hermopia  CHORESCA Jr  Heisuke  NAKAGAWA 《Fisheries Science》2002,68(3):478-483

ABSTRACT: A series of experiments were conducted to examine the effects of salinity, aeration and light intensity on oil globule absorption, feeding incidence, and growth and survival of early-stage Epinephelus coioides larvae. Newly hatched larvae were transferred to 40-L aquaria at a density of 1500 individuals/aquarium. Larvae were exposed to different levels of aeration (0 mL/min per L, 0.62 mL/min per L, 1.25 mL/min per L, 2.50 mL/min per L, or 3.75 mL/min per L); salinity (8 ppt, 16 ppt, 24 ppt, 32 ppt, or 40 ppt); and light intensity (0 lx, 120 lx, 230 lx, 500 lx, or 700 lx) for 4–6 days. Twenty larvae were sampled daily at 11:00 hours to measure for total length (TL), oil globule volume, and feeding incidence. Survival rates were determined by counting the total number of larvae remaining in each aquarium at the end of the experiment. Significantly higher survival rates ( P   <  0.05) were observed at aeration levels of 0.62 mL/min per L and 1.25 mL/min per L, at salinity levels of 16 ppt and 24 ppt, and at light intensities of 500 lx and 700 lx. The influence of aeration level, salinity and light intensity on oil globule absorption, feeding incidence, and growth and survival of early-stage grouper larvae are discussed.  相似文献   

Differences in food composition between territorial and aggregative juvenile crimson sea bream Evynnis japonica     

KOSAKU  YAMAOKA  MADOKA  SASAKI  TAKAYA  KUDOH  MASARU  KANDA 《Fisheries Science》2003,69(1):50-57

ABSTRACT:   Food composition, fork length and condition factor of juvenile crimson sea bream Evynnis japonica were examined for two behaviorally distinct types of fish inhabiting a nursery ground. Studies were carried out from March to September 1996 at Morode Cove, Ehime Prefecture, Japan. One type of fish is solitary and territorial and the other type is aggregative. The food compositions of the two types of fish were different. Solitary fish foraged mainly on Gammaridea and Caprellidea (benthic organisms), and Copepoda (planktonic organisms); while aggregative fish foraged mainly on Copepoda, Appendiculata and Cladocera (planktonic organisms). These findings suggest that when we study food composition of E. japonica , it is imperative to consider whether the samples used for the analyses are from solitary (territorial) fish. Solitary fish showed significantly greater fork length and condition factor than aggregative fish, suggesting that the former will have a greater fitness value than the latter.  相似文献   

Potential smolting ability of stream-dwelling Dolly Varden Salvelinus malma     

Daisuke  KISHI  Koji  MAEKAWA 《Fisheries Science》2003,69(6):1301-1302

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临夏草地畜牧业资源的开发利用     

马忠魁 《草业科学》1991,8(1):55-58

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Influence of reward level on vertical distribution and growthof rainbow trout Oncorhynchus mykiss fed on demand with self-feeders     

WEI-MIN  CHEN  MITSUO  TABATA 《Fisheries Science》2003,69(2):331-336

ABSTRACT:   The influence of reward level on vertical distribution and growthwas examined in rainbow trout fed on demand with self-feeders. Groupsof 15 trout with initial body weight of 140 g were maintainedat 14°C and feed access was restricted to a 12-h photophase.The trout received three reward levels with triplicates: 0.051 (low),0.089 (medium) and 0.267 g/kg fish/triggeractuation (high). Vertical distribution in the higher reward groupswas generally more even than that in the lower-reward groups, butthe behavioral characteristics of some individuals in a group couldplay an important role in determining vertical distribution. Moreover,no fish including the individuals responsible for trigger actuation,occupied the vicinity of a trigger. The small groups of 15 troutreceiving the medium-reward level obtained as much feed and grewas fast as the high-reward groups, but this was not the case forthe low-reward groups.  相似文献   

Testicular development and serum steroid hormone levels in captive male spotted halibut Verasper variegatus     

Yasunori  KOYA  Hiroki  WATANABE  Kiyoshi  SOYANO  Kengo  OHTA  Masato  ARITAKI  Takahiro  MATSUBARA 《Fisheries Science》2003,69(4):792-798

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Spontaneous mosaicism occurred in normally fertilized and gynogenetically induced progeny of the kokanee salmon Oncorhynchus nerka     

MINORU  TANAKA  SHIZUO  KIMURA  TAKAFUMI  FUJIMOTO  SUZU  SAKAO  ETSURO  YAMAHA  KATSUTOSHI  ARAI 《Fisheries Science》2003,69(1):176-180

ABSTRACT:   In normally fertilized progeny of the kokanee salmon Oncorhynchus nerka , DNA content flow cytometry revealed that all the externally normal embryos were diploid, whereas abnormal embryos exhibited haplo-diploid, diplo-tetraploid and haplo-diplo-tetraploid mosaicisms, together with a few haploid and diploid individuals. When gynogenetic development was artificially induced by fertilization of eggs obtained from a female of the same kokanee brood stock with UV-irradiated sperm, haplo-diploid mosaics appeared most frequently. These mosaics were likely to happen by certain cytological events, such as meiotic or mitotic errors during the process of maturation, fertilization or early cleavage.  相似文献   

Discrimination and abundance estimation of wild and released abalone Haliotis diversicolor using stable carbon and oxygen isotope analysis in north-eastern Taiwan     

YING-CHOU  LEE  HUANG-HAUR  KUO  YUE-GAU  CHEN 《Fisheries Science》2002,68(5):1020-1028

The discrimination between wild and released Taiwan abalone Haliotis diversicolor was performed by stable carbon isotope analysis. Abalone samples were collected from Mao Aw Gulf in north-eastern Taiwan. Live abalone and dead shells were collected by divers with an 80 × 80 cm frame. The densities and amounts of wild and released abalone, as well as the survival rates of released abalone, in 1997 and 1998 were estimated. The age of the specimens was also determined from the specific temperature of each month and the inverse relationship between oxygen isotope values and temperatures. Results show that examining stable isotopic profiles proves to be a practical and feasible method for stock discrimination as well as density and abundance estimation. These data would be helpful in assessing the success of abalone culture and release programs, which aim to enhance this valuable marine resource.  相似文献   

Annual reproductive cycle of black rockfish Sebastes schlegeli in captivity     

HISANARI  MORI  MASAHIRO  NAKAGAWA  KIYOSHI  SOYANO  YASUNORI  KOYA 《Fisheries Science》2003,69(5):910-923

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Inheritance mode of seed dormancy in the hybrid progeny of sesame,Sesamum indicum,and its wild relative,Sesamum mulayanum Nair     

EIJI TANESAKA  EIKO UMEDA  MASAYUKI YAMAMOTO  KYOJIRO MASUDA  KYOJI YAMADA  MOTONOBU YOSHIDA 《Weed Biology and Management》2012,12(2):91-97

Sesamum mulayanum is a wild relative of cultivated sesame, Sesamum indicum, and sometimes grows in sesame crop fields as an associated weed. This species shows deep seed dormancy and is characterized by conspicuous purple pigmentation on the lower lip of the corolla. The present study examined the inheritance mode of seed dormancy by using reciprocal progeny from crosses between the two species. The seeds of S. indicum and F₁ (S. indicum×S. mulayanum) showed good germination, but those of S. mulayanum and F₁ (S. mulayanum×S. indicum) showed deep dormancy. The F₂ seeds from both reciprocal crosses showed deep dormancy. These results, combined with the maternal inheritance of seed‐coat characteristics, indicated that the seed dormancy of S. mulayanum can be attributed to its seed‐coat structure (coat‐enhanced dormancy). The F₃ (S. indicum×S. mulayanum) seeds varied in their depth of seed dormancy and those seeds with deep dormancy (<50% germination) and those with no or shallow dormancy (≥50% germination) occurred in the expected ratio of 3:1, indicating that this trait is polygenic but is controlled by a single dominant major gene. The purple pigmentation of the corolla was expressed in both reciprocal F₁ plants and the presence and absence of pigmentation was segregated among the F₂ plants at the expected ratio of 3:1, indicating that this trait is also controlled by a single dominant gene. The segregation of the major gene controlling seed dormancy and that controlling purple pigmentation was not independent (9:3:3:1), indicating that these genes are linked, providing insights on sesame domestication.  相似文献