13 documents found, page 1 of 2
Fecundity and sex steroid profile in boarfish Capros aper
Sequeira, Vera; Couto, Elsa; Neves, Ana; Vieira, Ana Rita; Canario, Adelino; Gordo, Leonel SerranoThe boarfish Capros aper is one of the most commonly discarded non-commercial species in the International Council for the Exploration of the Sea (ICES) Subdivision VIII in the Atlantic. An increasing interest in this fishery and an incomplete knowledge on the status of the stock justified the present investigation focused on the determination of fecundity type and its estimation, supported by sex steroid profi...
Sex steroids of black scabbardfish, Aphanopus carbo, in relation to reproductiv...
Farias, I.; Couto, Elsa; Lagarto, N.; Delgado, J.; Canario, Adelino; Figueiredo, I.Black scabbardfish, Aphanopus carbo, is a commercially important species that takes distant migrations throughout its life cycle. Sex steroids were measured by radioimmunoassay in the blood plasma of specimens caught off the Madeira Archipelago and mainland Portugal to link this species migratory path with its reproductive cycle. Furthermore, a pilot study using Mozambique tilapia (Oreochromis mossambicus) was ...
Zygoparity and sex steroid hormone profiles in bluemouth Helicolenus dactylopterus
Sequeira, V.; Couto, Elsa; Neves, A.; Vieira, A. R.; Paiva, R. B.; Canario, A.V.M.; Gordo, L. S.Two hundred and seven individuals (103 females and 104 males) of bluemouth Helicolenus dactylopterus (Scorpaeniformes, Sebastidae), a commercially important deep-water species with an unusual reproductive strategy, from the eastern Atlantic Ocean ranging from 13<bold></bold>9 to 37<bold></bold>5 cm total length (L-T) were analysed from September 2011 to October 2012. The analysis included gonad maturity phases ...
How integrated are behavioral and endocrine stress response traits? A repeated ...
Boulton, Kay; Couto, Elsa; Grimmer, Andrew J.; Earley, Ryan L.; Canario, Adelino V. M.; Wilson, Alastair J.; Walling, Craig A.It is widely expected that physiological and behavioral stress responses will be integrated within divergent stress-coping styles (SCS) and that these may represent opposite ends of a continuously varying reactive-proactive axis. If such a model is valid, then stress response traits should be repeatable and physiological and behavioral responses should also change in an integrated manner along a major axis of a...
Plasma steroid hormone levels in female flounder Platichthys flesus and the inf...
Damasceno-Oliveira, A.; Fernández-Durán, B.; Gonçalves, J. M. S.; Couto, Elsa; Canario, Adelino V. M.; Coimbra, JoséThe reproductive cycle in teleosts is timed to guarantee that eggs hatch in the right place at the right time, with environmental factors playing important roles in entraining and controlling the entire process. The effects of some environmental factors, like temperature and photoperiod, are now well understood. There are only a few studies regarding the effects of hydrostatic pressure (HP) on the reproductive ...
Free androgens and progestins and their conjugated forms in serum and urine of ...
Bayunova, L.; Canario, Adelino V. M.; Semenkova, T.; Couto, Elsa; Gerasimov, A.; Barannikova, I.Stellate sturgeon (Acipenser stellatus Pallas) males from Volga River treated with LH-RH-A showed an increase of free, sulfated and glucuronided sex steroid levels in serum and urine at spermiation. Conjugated forms of sex steroids could act as pheromones in sturgeon.
Levels of free and conjugated androgens and progestins in coelomic fluid and se...
Bayunova, L.; Semenkova, T.; Canario, Adelino V. M.; Couto, Elsa; Gerasimov, A.; Barannikova, I.Stellate sturgeon (Acipenser stellatus Pallas) females from the Volga River were analysed for sex steroids after hormonal stimulation. The results show a significant increase of sulfated sex steroid levels in serum and coelomic fluid (CF) at final maturation (FM). It is hypothesized that the steroid metabolites could be part of a chemical communication system related to reproduction.
Ovarian development and plasma sex steroid levels in cultured female Senegalese...
Garcia-Lopez, A.; Couto, Elsa; Canario, Adelino V. M.; Sarasquete, C.; Martínez-Rodriguez, G.Ovarian development was studied in cultured female Senegalese sole Solea senegalensis. Females with regressed ovaries, mainly occupied by perinucleolar oocytes, predominated throughout summer exhibiting low condition factor (K), gonadosomatic index (IG), and plasma 17β-estradiol and testosterone levels. Throughout autumn and winter (ovaries at early and intermediate maturation), oocytes progressed to cortical a...
Testicular development and plasma sex steroid levels in cultured male Senegales...
Garcia-Lopez, A.; Fernandez-Pasquier, V.; Couto, Elsa; Canario, Adelino V. M.; Sarasquete, C.; Martínez-Rodriguez, G.Testicular development and plasma levels of sex steroids (11-ketotestosterone (11-KT), testosterone (T) and 17,20 -dihydroxy-4-pregnen-3-one (17,20 -P)) were investigated for the Wrst time in cultured male Senegalese sole Solea senegalensis. The germ cell dynamics and gonadosomatic index (IG) were monitored. Based on the relative abundance of the diVerent types of germ cells present, the spermatogenetic cycle w...
Sex steroids and oocyte maturation in the sterlet (Acipenser ruthenus L.)
Semenkova, T.; Canario, Adelino V. M.; Bayunova, L.; Couto, Elsa; Kolmakov, Nikolai N.; Barannikova, I.Sturgeon oocytes, like those of other vertebrates, are arrested in early meiosis and require a steroid or steroids to trigger meiosis resumption or maturation. The identity of the maturation-inducing steroid in sturgeons has present study was designed to investigate in sterlet the follicular secretion and relative blood changes of free and conjugated 17,20βP, 20βS and of the androgens T, 11KT, in response to ho...