Data/hora: 08/06/2024 18:42:53

Provedor de dados: 	Institutional Archive of Ifreme (ArchiMer)	
País: 	France	
Título: 	Reproduction and growth of the deep-sea brittlestar ophiura-ljungmani (lyman)	
Autores: 	Tyler, Pa; Gage, Jd.	
Data: 	1980	
Ano: 	1980	
Palavras-chave: 	Ovocytes; Fécondité; Structure de la répartition des classes de tailles; Recrutement; Capacité de survie; Oocytes; Fecundity; Population structure; Recruitment; Survivorship.	
Resumo: 	Reproductive biology and population dynamics of Ophiura Ijungmani were studied by measuring disk diameters and by examining oocyte size-frequencies and fecundity from a sequential seasonal series of large samples from a 2900 m deep Permanent Station in the Rockall Trough (Northeast Atlantic). Egg size (max. 90 !lm) and fecundity (up to 57000 eggs per individual) suggests indirect planktotrophic development, while a clear annual cycle in gametogenesis, with probably synchronous spawning in JanuaryFebruary, confirms a marked seasonality that is also seen as an annual, summertime set of postlarvae on to the bottom. Analysis of size structure of the population indicates annually discrete year classes with a maximum longevitv of around 10 years. lndividuals show fastest growth and lowest survivorship as postlarvae with a higher survivorship and lower growth rate of about 1 mm. yr- 1 among sizes &gt; 1.5 mm. Reproductive maturity is reached in the third year at 3.5-4.0 mm with individuals thereafter probably reproducing annually. Possible factors controlling the annual cycle in the supposedly seasonless deep sea are discussed in relation to the possible significance of a likely seasonal pattern in downward flux of organic particles derived from surface production.	
Tipo: 	Text	
Idioma: 	Inglês	
Identificador: 	http://archimer.ifremer.fr/doc/00323/43424/43087.pdf

http://archimer.ifremer.fr/doc/00323/43424/	
Editor: 	Gauthier-villars	
Formato: 	application/pdf	
Fonte: 	Oceanologica Acta (0399-1784) (Gauthier-villars), 1980 , Vol. 3 , N. 2 , P. 177-185	
Fonte: 	Gauthier-Villars

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