نتایج جستجو برای: carcharhinus dussumieri
تعداد نتایج: 586 فیلتر نتایج به سال:
تحقیق حاضر به منظور بررسی انگلهای خارجی و دستگاه گوارش ماهی گل خورک (boleophthalmus dussumieri) به مدت 6 ماه از دی ماه 1390 تا خرداد ماه 1391 در منطقهی خورآبی ساحل بندرعباس انجام شد. در طول تحقیق، 69 نمونهی ماهی به روش دستی صید و به صورت زنده به آزمایشگاه منتقل گردید. انگلهای جداسازی شده از دستگلاه گوارش در محلول فرمالین 4% تثبیت و به منظور نگهداری به اتانول 70% منتقل شد. در طول دورهی ب...
The increasing demand for shark fins in Asia, and the publicity resulting from finning and discarding live sharks, has generated concern regarding the sustainability of the world’s shark populations. These concerns can be attributed to the shark’s life history, which is characterized by a pattern of slow growth, late maturity, few offspring, and long life, making populations vulnerable to overe...
BACKGROUND Quantifying genetic diversity and metapopulation structure provides insights into the evolutionary history of a species and helps develop appropriate management strategies. We provide the first assessment of genetic structure in spinner sharks (Carcharhinus brevipinna), a large cosmopolitan carcharhinid, sampled from eastern and northern Australia and South Africa. METHODS AND FIND...
The northwestern Indian Ocean harbors a number of larger marine vertebrate taxa that warrant the investigation of genetic population structure given remarkable spatial heterogeneity in biological characteristics such as distribution, behavior, and morphology. Here, we investigate the genetic population structure of four commercially exploited shark species with different biological characterist...
Longline fishing is the most common elasmobranch capture method around the world, yet the physiological consequences of this technique are poorly understood. To quantify the sub-lethal effects of longline capture in the commonly exploited Caribbean reef shark (Carcharhinus perezi), 37 individuals were captured using standard, mid-water longlines. Hook timers provided hooking duration to the nea...
Detecting and determining the validity of local extinctions is an important conservation measure in order to uncover management failures. There are quantitative and qualitative methods that estimate extinction probability based on past sighting records. However, because current baselines about species’ abundances and distributions in the sea were mostly established after humans had started affe...
Empirical data on the abundance and habitat preferences of coral reef top predators are needed to evaluate their ecological impacts and guide management decisions. We used longline surveys to quantify the shark assemblage at French Frigate Shoals (FFS) atoll from May to August 2009. Fishing effort consisted of 189 longline sets totaling 6,862 hook hours of soak time. A total of 221 sharks from ...
Blacktip reef sharks Carcharhinus melanopterus were the most abundant predator in the lagoons at Palmyra Atoll. They were evenly distributed throughout the lagoons, although there was some evidence of sexual segregation. Males reach sexual maturity between 940-1,020 mm L(T). Bird remains were found in some C. melanopterus stomachs. C. melanopterus at Palmyra appear to be smaller than those at o...
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