نتایج جستجو برای: induced spawning
تعداد نتایج: 985695 فیلتر نتایج به سال:
Background: Catecholamines and cortisol are stress hormones in teleosts secreted, respectively, by the adrenal homologs, chromaffin and interrenal tissues. It is well known that the stress hormones respond to a variety of stress stimuli, induced or natural. There is a cross-talk between the stress and reproductive axis but the physiological implications are debated. It is believed that breeding...
The natural reproductive ecology of freshwater eels remained a mystery even after some of their offshore spawning areas were discovered approximately 100 years ago. In this study, we investigate the spawning ecology of freshwater eels for the first time using collections of eggs, larvae and spawning-condition adults of two species in their shared spawning area in the Pacific. Ovaries of female ...
Venture capital funds have been facing increasing regulatory scrutiny since the 2007 financial crisis, particularly in respect of calls for increased disclosure requirements. In this paper, we examine whether more stringent securities regulation helps or hinders the supply and performance of venture capital as well as new business creation (i.e., entrepreneurial spawning). Based on data from 34...
Spawning aggregations form when fishes migrate to a site from their normal feeding grounds and form temporary groupings for breeding. Spawning aggregation sites are spatially rare, and demonstrating differences between a spawning aggregation site and unselected sites nearby is the first step towards understanding the benefits provided by the aggregation site. Chromis hypsilepis (Pomacentridae) ...
—During the spawning season, adult striped bass Morone saxatilis can occur outside known spawning tributaries. This phenomenon has been observed in other fishes, suggesting that investigators have misspecified reproductive schedules by assuming annual spawning. Across a range of species, skipped (i.e., nonannual) spawning is positively correlated with longevity. Therefore, reproductive schedule...
The reproductive behaviour of the kelp bass Paralabrax clathratus was studied on Santa Catalina Island, California, U.S.A. from April 2000 to September 2002. Adults formed aggregations of three to > 200 individuals, and spawning occurred within subgroups of three to 23 individuals that contained a single female. The gonado-somatic index (IG) of collected ripe males (mean 1⁄4 5 8%, range 1⁄4 0 5...
the present paper studies the reproductive biology, maturation size and sex ratio of penaeus monodon collected from digha fishing grounds, india during 2011-2013. a total of 633 individual of p. monodon were examined and among them 242 were males and 391 were females. the overall yearly sex ratio was observed to be 1:1.6 (males: females). based on the results, the spawning season of p. monodon...
Correction: Spawning Site Selection and Contingent Behavior in Common Snook, Centropomus undecimalis
Reproductive behavior affects spatial population structure and our ability to manage for sustainability in marine and diadromous fishes. In this study, we used fishery independent capture-based sampling to evaluate where Common Snook occurred in Tampa Bay and if it changed with spawning season, and passive acoustic telemetry to assess fine scale behavior at an inlet spawning site (2007-2009). S...
Many large groupers form spawning aggregations, returning to the same spawning sites in consecutive spawning seasons. Connectivity between spawning aggregations is thus assured by larval dispersal. This study looks into the genetic structure and gene flow among spawning aggregations of a large grouper, the gulf coney Hyporthodus acanthistius, in the northern Gulf of California. First, using the...
The effects of castration on male spawning behavior, nestbuilding and fertility were measured in a five day spawning trial with an intact female. Spawning and fertility decreased one week following castration while nestbuilding was unaffected. Sham operated males showed normal spawning and fertility. Two weeks postoperatively, fertility and spawning were increased paralleling partial regenerati...
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