نتایج جستجو برای: spawning induction
تعداد نتایج: 204295 فیلتر نتایج به سال:
Spawning salmon create patches of disturbance through redd digging which can reduce macroinvertebrate abundance and biomass in spawning habitat. We asked whether displaced invertebrates use non-spawning habitats as refugia in streams. Our study explored how the spatial and temporal distribution of macroinvertebrates changed during a pink salmon (Oncorhynchus gorbuscha) spawning run and compared...
Tenualosa ilisha (Hamilton) is a valuable migratory fish belonging to the family Clupeidae and it is distributed in a wide area from the Persian Gulf to coasts of Pakistan and China’s southern sea. The aim of the present study was to investigate the changes occurring in innate immunity parameters during upstream migration and comparing them to those during post spawning. Sixty mature female hil...
Photoperiod and temperature are well-established environmental cues for gonadal growth in seasonally reproducing organisms. The photoperiod is known to regulate seasonal reproduction via induction of thyroid hormone regulating genes the saccus vasculosus (SV) fishes. However, SV absent many breeding fishes, including Heteropneustes fossilis. H. fossilis a long-day catfish which recrudescence be...
The effectiveness of two kinds of dopamine antagonist (DA), metoclopramide (Met) and domperidone (Dom) combined with the gonadotropin releasing hormone analogue (D-Ala6, Des Gly10 ethylamide) GnRHa was assayed on the ovulation success, latency period, ovulation index (OI) and fertilization success of kutum, Rutilus frisii kutum (Kamenskii, 1901). Brood fish were injected intra-peritoneally as f...
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 ...
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) ...
In fish, oocyte meiotic maturation is regulated by 17α, 20β-dihydroxy-progesterone through cAMP. To study the role of cAMP response element binding protein (CREB) in meiotic maturation, we cloned and characterized the expression pattern of CREBs from two fish models, the Nile tilapia and catfish. In the Nile tilapia three different CREBs were identified where in CREB1 was found in many tissues ...
Combinations of progesterone, lutenizing hormone releasing hormone analogue (LHRHa), human chorionic gonadotrophin (hCG), and the dopamine-2 (DA2) receptor antagonist 1-[1-[4,4-bis(4-Fluorophenyl)butyl]-4-piperidinyl]-1,3-dihydro-2H-benzimidazol-2-one (Pimozide; Orap) were tested for improvement of spawning rates, oocyte numbers, fertilization and neurulation rates of the Fowler toad (Bufo fowl...
—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...
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