نتایج جستجو برای: spawning biomass per recruit

تعداد نتایج: 511440  

2005
E. A. WHITEMAN C. A. JENNINGS R. S. NEMETH

Ultrasonic imaging was used to determine the spawning population structure and develop a fecundity estimation model for a red hind Epinephelus guttatus spawning aggregation within the Red Hind Bank Marine Conservation District, St Thomas, U.S.V.I. The spawning population showed considerable within-month and between-month variation in population sizeand sex-structure. In the spawning season stud...

2014
Chi-Hoon Lee Bong-Kiun Kaang Young-Don Lee

This study was investigated spawning behavior, structure of egg masses and egg development in Aplysia kurodai inhabiting the coastal waters of Jeju Island, Korea. The mating and courtship behavior of A. kurodai occurred in the form of unilateral copulating with chain formation. In chain copulation, only the first animal acted as a female; the second and succeeding animals acted as males (sperm ...

2012
Andrew O. Shelton Stephan B. Munch David Keith Marc Mangel

Understanding the process of recruitment is fundamental to fisheries biology and management. However, recruitment in natural populations is highly variable and rarely well described by classical stock–recruitment relationships (SRRs). Recent analyses suggest that the age composition of the spawning biomass may play an important role in the mismatch between SRRs and data. Here we develop a gener...

2013
Emer Morgan Ruth M O' Riordan Sarah C Culloty

Climate variability and the rapid warming of seas undoubtedly have huge ramifications for biological processes such as reproduction. As such, gametogenesis and spawning were investigated at two sites over 200 km apart on the south coast of Ireland in an ecosystem engineer, the common cockle, Cerastoderma edule. Both sites are classed as Special Areas of Conservation (SACs), but are of different...

Journal: :Zebrafish 2012
Ngawang Gonsar Adelle C Schumann Jerica N Buchard Jennifer O Liang

Zebrafish in our laboratory are usually bred by removing the fish from the recirculating aquatic system and placing them into 1-2 L spawning tanks. These spawning tanks consist of a bottom reservoir, a lid, and an insert that fits in closely into the bottom reservoir. When the fish breed, the eggs fall through holes of the insert and into the reservoir, thus preventing them from being cannibali...

2005
Bernard A. Megrey Yong-Woo Lee Allen Macklin

Many of the factors affecting recruitment in marine populations are still poorly understood, complicating the prediction of strong year classes. Despite numerous attempts, the complexity of the problem often seems beyond the capabilities of traditional statistical analysis paradigms. This study examines the utility of four statistical procedures to identify relationships between recruitment and...

Journal: :شیلات 0
فاطمه شاکری1 1. کارشناسی ارشد تکثیروپرورش آبزیان، گروه شیلات، دانشکده منابع طبیعی، دانشگاه تهران محمدعلی نعمت اللهی2 2. دانشیار گروه شیلات، دانشکده منابع طبیعی، دانشگاه تهران آرش جوانشیر2 2. دانشیار گروه شیلات، دانشکده منابع طبیعی، دانشگاه تهران ابوالقاسم روحی3 3 .استادیار سازمان تحقیقات و آموزش جهادکشاوزری، موسسه تحقیقات علوم شیلاتی، پژوهشکده اکولوژی دریای خزر ساری

the present study carried out an in vitro experiment on effects of salinity and temperature on acartia tonsa life cycle from caspian sea. during the experiment, temperature and salinity ranged 25, 27, 29 ± 1 °c and 12‰ and 17‰, respectively within a period of 60 days. spawning rate was measured using mesh size of 100 µ planktonic net from surface to 10 m depth. early results show that nauplii a...

Journal: :Ecological applications : a publication of the Ecological Society of America 2013
Paul Humphries Adam Richardson Glenn Wilson Tanya Ellison

We present and test an extension of the "match/mismatch" hypothesis that attempts to explain the persistence, under conditions of flow alteration, of small, short-lived, native, riverine, fish species. The premise is that flow alteration typically changes environmental conditions, such as temperature and prey abundance, which may affect survival during the larval period of fishes. This "window-...

2016
Francoise Cavada-Blanco Ainhoa L. Zubillaga Carolina Bastidas

Phytoplankton drives primary productivity in marine pelagic systems. This is also true for the oligotrophic waters in coral reefs, where natural and anthropogenic sources of nutrients can alter pelagic trophic webs. In this study, microphytoplankton assemblages were characterized for the first time in relation to expected coral spawning dates in the Caribbean. A hierarchical experimental design...

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