|
|
|
| Registros recuperados: 84 | |
|
| |
|
| |
|
| |
|
|
| Garrigue, C; Derville, S; Bonneville, C; Baker, Cs; Cheeseman, T; Millet, Laurent; Paton, D; Steel, D. |
| Humpback whales Megaptera novaeangliae were severely depleted by commercial whaling. Understanding key factors in their recovery is a crucial step for their conservation worldwide. In Oceania, the Chesterfield-Bellona archipelago was a primary whaling site in the 19th century, yet has been left almost unaffected by anthropogenic activities since. We present the results of the first multidisciplinary dedicated surveys in the archipelago assessing humpback whale populations 2 centuries post-whaling. We encountered 57 groups during 24 survey days (2016-2017), among which 35 whales were identified using photographs of natural markings (photo-ID), 38 using genotyping and 22 using both. Humpback whales were sparsely distributed (0.041 whales km-1): most... |
| Tipo: Text |
Palavras-chave: Chesterfield-Bellona archipelago; Connectivity; Coral Sea; Habitat use; Humpback whale; Satellite tracking; Sex ratio; Whaling. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00632/74454/74267.pdf |
| |
|
| |
|
|
| Debas, L; Fostier, A; Fuchs, Jacques; Weppe, M; Nedelec, Georges; Benett, A; Cauty, C; Jalabert, B. |
| The Polynesian grouper, Epinephelus microdon , was chosen as an experimental model in order to investigate about factors controlling sexuality in groupers. |
| Tipo: Text |
Palavras-chave: French Polynesia; Epinephelus microdon; Sex ratio; Sexual maturity; Sex hormones; Sex determination; Sex; Fish culture; Endocrinology; Reproduction; Sex reversal; Animal morphology. |
| Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/1989/acte-1439.pdf |
| |
|
|
| Vandeputte, Marc; Clota, Frederic; Sadoul, Bastien; Blanc, Marie-odile; Blondeau-bidet, Eva; Bégout, Marie-laure; Cousin, Xavier; Geffroy, Benjamin. |
| Temperature‐dependent sex determination (TSD) can be observed in multiple reptile and fish species. It is adaptive when varying environmental conditions advantage either males or females. A good knowledge of the thermosensitive period is key to understand how environmental changes may lead to changes in population sex ratio. Here, by manipulating temperature during development, we confirm that cold temperature (16°C) increases the proportion of fish that develop as females in European sea bass (Dicentrarchus labrax) until 56 days posthatching, but show that it has an opposite effect at later stages, with the proportion of males reaching ~90% after 230 days at 16°C. This is the first observation of opposite effects of temperature at different time periods... |
| Tipo: Text |
Palavras-chave: Dicentrarchus labrax; Fish; Sex ratio; Temperature-dependent sex determination; Thermosensitive period; TSD. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00658/76965/78184.pdf |
| |
|
| |
|
|
| Vandeputte, Marc; Dupont Nivet, M; Chavanne, H; Chatain, Beatrice. |
| Polygenic sex determination, although suspected in several species, is thought to be evolutionarily unstable and has been proven in very few cases. In the European sea bass, temperature is known to influence the sex ratio. We set up a factorial mating, producing 5.893 individuals from 253 full-sib families, all reared in a single batch to avoid any between-families environmental effects. The proportion of females in the offspring was 18.3%, with a large variation between families. Interpreting sex as a threshold trait, the heritability estimate was 0.62 +/- 0.12. The observed distribution of family sex ratios was in accordance with a polygenic model or with a four-sex-factors system with environmental variance and could not be explained by any genetic... |
| Tipo: Text |
Palavras-chave: Dicentrarchus labrax; Fish; Growth; Heritability; Sex ratio. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3526.pdf |
| |
|
| |
|
|
| Oddone,M. Cristina; Amorim,Alberto F. de; Mancini,Patrícia L.; Norbis,Walter. |
| Specimens of Rioraja agassizi were collected monthly off Santos, Southeast Brazil, between latitudes 23º37'S and 27º40'S, from March, 2005 to March, 2006. A total number of 278 males and 1023 females were captured. Observed depth range was 10-120 m, being the species absent above 120 m. Sex ratio significantly favored females. The entire length range of R. agassizi was observed. Females ranged in length from 16.0 to 59.4 cm and males from 13.0 to 47.2 cm. Mean female length was significantly higher than that of males. For grouped length distributions, asymmetry patterns were observed in both sexes. Length-width functions were sexually dimorphic. Males with lengths < 24.5 cm were relatively wider than females. Length-total weight curves were... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Skates; Depth; Total length; Elasmobranch; Sex ratio. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252007000300021 |
| |
|
|
| Martins-Queiroz,Mirian F.; Mateus,Lúcia A. de F.; Garutti,Valdener; Venere,Paulo C.. |
| The study of the reproductive biology of Triportheus trifurcatus of the middle rio Araguaia was carried out using 275 specimens obtained in seven collections conducted in the period between November 2003 and January 2005. Females prevailed among the classes of intermediate length, as well as in the total number of samples. On the other hand, males prevailed in the smaller classes. The average length of females was larger than that of males. Four stages of gonadal maturation were macro- and microscopically identified: B - maturation, C - mature, D - spent and E - resting. Stage A (immature) was not found in the habitats sampled. The smallest-length male was 110 mm in standard length, and the smallest female, 119 mm. The spawning period occurred from... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fecundity; Sex ratio; Reproductive cycle; Gonadal maturation. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000200010 |
| |
|
|
| Neuberger,Andréa L.; Marques,Elineide E.; Agostinho,Carlos S.; Oliveira,Rafael J. de. |
| In order to evaluate aspects of the reproductive biology of Rhaphiodon vulpinus in the Upper and Middle Tocantins River, samples were taken monthly from October, 1999 through September, 2001, by means of gill nets. Males, which were more abundant than females (chi2 146.87: df=1: p<0.05), matured at a smaller size. The reproductive period of the species extended essentially from November through January, with a peak of activity in November. Fecundity, with an estimated mean value of 98,185 oocytes, varied from 38,177 to 215,841 oocytes, and it did not correlate with the length of the individual female analyzed (r=0.4663: p=0.206). Relative fecundity was 130.6 oocytes/g total weight. Mature oocytes had a mean diameter of 0.98 mm, corresponding to a volume... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sex ratio; First maturation; Reproduction; Fecundity. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252007000400007 |
| |
|
| |
|
| |
|
| |
|
|
| 林, 佐季; 仲島, 義貴. |
| We investigated effects of sugar solution on adult longevity, progeny production and progeny sex ratio of Aphidius ervi in the presence and absence of host aphids. When female parasitoids were provided with 50% glucose–fructose solution in 1 : 1 ratio, they lived approximately twice longer than those provided with distilled water, irrespective of host aphid provision. The same effect of sugar solution was also observed on progeny production. When the parasitoid was fed sugar solution, its lifetime progeny production approximately doubled in comparison to that provided with water, whereas daily progeny production did not differ. Total number of female progeny did not differ between adult female provided with water and sugar solution, but significantly... |
|
Palavras-chave: Biological control; Sex ratio; Sugar; Longevity; Fecundity. |
| Ano: 2014 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4035 |
| |
|
| |
|
|
| Bouriga, N.; Cherif, M.; Hajjej, Gh.; Guignard, J-P.; Faure, E.; Trabelsi, M.. |
| Le présent travail porte sur l’étude des caractères biométriques des athérines de Tunisie pour compléter les études métriques et méristiques établies auparavant. L’objectif principal de cette étude, est de comparer les paramètres biologiques via l’analyse de la croissance et de la reproduction de Atherina boyeri (côtes nord tunisiennes) et Atherina lagunae (île Kerkennah). L’étude de la sex-ratio en fonction des mois a montré que les femelles sont toujours plus nombreuses que les mâles pour les espèces d’athérines. En effet, la valeur globale de la sex-ratio, toute taille confondue, est en faveur des femelles. L’étude du cycle sexuel des athérines insulaires des îles Kerkennah a montré que la période de reproduction s’établie entre le mois de mars et le... |
| Tipo: Journal Contribution |
Palavras-chave: Coastal lagoons; Sex ratio; Growth rate; Length-weight relationships; Spawning seasons. |
| Ano: 2010 |
URL: http://hdl.handle.net/1834/4693 |
| |
|
| |
| Registros recuperados: 84 | |
|
|
|
