Plasma steriod hormone concentrations in relation to reproductive cycle of the sweep Scorpis lineolatus (Kyphosidae) caught from the wild

1992 ◽  
Vol 43 (4) ◽  
pp. 753 ◽  
Author(s):  
M Deual ◽  
NW Pankhurst
Keyword(s):  
Steroid Hormones ◽  
Reproductive Cycle ◽  
Gonadosomatic Index ◽  
Plasma Concentrations ◽  
Plasma Testosterone ◽  
Hepatosomatic Index ◽  
Spawning Period ◽  
Testosterone Concentration ◽  
Low Concentrations ◽  
Advanced Stages

Changes in gonadosomatic index (GSI), hepatosomatic index (HSI), oocyte development and plasma levels of steroid hormones were studied during the reproductive cycle of the sweep Scorpis lineolatus. GSI values for both sexes were maximal in March and April. During this period the size distribution of oocytes showed a predominance of advanced stages of vitellogenesis, whereas males were completing spermatogenesis. However, staging data suggest that spawning may not begin until April. HSI was maximal 2 months prior to the beginning of gametogenesis in both sexes. Plasma concentrations of oestradiol-17β in females increased rapidly from February, reached a peak (2.3 ng mL-1) in association with the end of vitellogenesis in March, and returned to low concentrations in May and June. Plasma concentrations of 17α,20α-dihydroxy-4-pregnen-3-one (17,20βP) also peaked in March in females, but 17,20βP was generally not detectable in males. Plasma testosterone concentration peaked along with other steroids in March in females but showed no significant change in males. Plasma ll-ketotestosterone (1 1KT) concentration was maximal in males before spawning (February), but was not elevated during the spawning period itself. Changes in oestradiol-17β and testosterone in association with vitellogenensis in females are consistent with those reported for other teleosts, whereas changes in 17,20βP, testosterone and 11-ketotestosterone in males are different from those previously reported.

Testosterone sensitivity of the seminal sacs of tree sparrows (Spizella arborea) in different reproductive states

1986 ◽  
Vol 109 (1) ◽  
pp. 125-131 ◽  
Author(s):  
F. E. Wilson
Keyword(s):  
Reproductive Cycle ◽  
Plasma Concentrations ◽  
Plasma Testosterone ◽  
Reproductive State ◽  
Critical Test ◽  
Testosterone Concentration ◽  
Unit Change ◽  
Dependent Growth ◽  
Dose Dependent ◽  
Short Days

ABSTRACT Testosterone sensitivity of the seminal sacs of castrated tree sparrows from each of three reproductive states was evaluated by measuring the change in seminal-sac mass per unit change in the logarithm of replacement or plasma testosterone. Birds were exposed to exogenous testosterone for 38 days. Replacement doses less than 0·17 μmol or plasma concentrations less than about 0·7 nmol/l did not induce seminal-sac growth in photosensitive castrated birds held on short days, in photosensitive castrated birds transferred from short to long days, or in photorefractory castrated birds retained on long days. Higher replacement doses or plasma concentrations, however, stimulated log dose-dependent growth of the seminal sacs in castrated birds from all three reproductive states. The change in seminal-sac mass per unit change in the logarithm of the dose of replacement testosterone was less (P= 0·0495) in photosensitive castrated birds held on short days than in photosensitive castrated birds transferred to long days. A more critical test of sensitivity (i.e. the change in seminal-sac mass per unit change in the logarithm of mean plasma testosterone concentration) indicated, however, that sensitivity of the seminal sacs to testosterone is independent of reproductive state. That result, when considered in the context of the plasma testosterone profile of intact males during a simulated reproductive cycle, argues that the seminal sacs of sexually quiescent (photosensitive or photorefractory) tree sparrows are small not because of their insensitivity to androgens, but because of a deficiency of circulating androgens. J. Endocr. (1986) 109, 125–131

Some aspects of reproductive biology of Gobius paganellus (Gobiidae) on the north-eastern coasts of Tunisia (Bizerta lagoon)

2013 ◽  
Vol 93 (8) ◽  
pp. 2235-2246 ◽  
Author(s):  
Ibtissem Louiz ◽  
Mossadok Ben Attia ◽  
Oum Kalthoum Ben Hassine
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Gonadosomatic Index ◽  
Length Distribution ◽  
Sexual Cycle ◽  
Hepatosomatic Index ◽  
Gobiid Fish ◽  
Spawning Period ◽  
North East ◽  
Bizerta Lagoon

The rock goby, Gobius paganellus one of the most common gobiid fish in Bizerta lagoon (north-east of Tunisia), is a gonochoric species that belongs to the Gobiidae family. This study provides the first detailed information of its reproductive biology in lagoon environments. Gobius paganellus was sampled monthly from January 2005 to December 2006 involving 1486 specimens. Total length distribution ranged between 38 and 125 mm. The maximum recorded total lengths were, respectively, 122 mm and 125 mm for female and male. Over the entire population, the sex-ratio was unbalanced in favour of females. According to months, a predominance of females sex-ratio was recorded during the spawning period while according to body size, males were dominating among larger size-classes. In both sexes, the variation of the gonadosomatic index (GSI) was independent of size. Macroscopic and microscopic examination of the gonads added to the monthly monitoring of gonadosomatic index and hepatosomatic index showed that gonads development begins in October and spawning period extends from December to March. The cyclic pattern of gonads development was determined by histology. Results indicated that G. paganellus exhibits a group-synchronous oocyte development. The sizes of first sexual maturity related to 50% of mature individuals were 78.3 mm (CI95: 77–84 mm) for males and 79 mm (CI95: 75–85 mms) for females. The discussion part underlined the impacts of some environmental factors and antropization of this lagoon on sexual cycle of G. paganellus.

Tissue biochemical composition in relation to the reproductive cycle of deep-sea decapod Aristeus antennatus in the Portuguese south coast

2003 ◽  
Vol 83 (5) ◽  
pp. 963-970 ◽  
Author(s):  
R. Rosa ◽  
M.L. Nunes
Keyword(s):  
Fatty Acids ◽  
Reproductive Cycle ◽  
Neutral Lipids ◽  
Gonadosomatic Index ◽  
Cholesterol Content ◽  
South Coast ◽  
Hepatosomatic Index ◽  
Maturity Stage ◽  
Lipid Levels ◽  
Aristeus Antennatus

Biochemical changes during the reproductive cycle of Aristeus antennatus (Crustacea: Decapoda) on the Portuguese south coast were investigated. Proximate chemical composition, lipid classes, fatty acid profiles, glycogen and cholesterol content were determined in the muscle, ovary and hepatopancreas (HP) during a period of one year (October 2000–September 2001). Gonadosomatic index (GSI) increased significantly in June and July and during the maturation process. Hepatosomatic index (HSI) also increased throughout the ovarian maturation. A positive correlation between lipid levels in the ovary and GSI (r=0.53, P<0.05) and HSI (r=0.30, P<0.05) was found. The muscle showed very low lipid levels and higher percentages of polar lipids. Higher proportions of neutral lipids, mainly triacylglycerols, were observed in both ovary and HP. Both ovarian and HP cholesterol increased with maturation. Protein and glycogen content in the muscle, ovary and HP did not vary as a function of ovary maturity stage. From the different tissues analysed, the glycogen is mainly stored in the HP and to a lesser extent in the muscle. In both ovary and HP the major fatty acids were 16:0, 18:1(n-7), 18:1(n-9), 20:5(n-3) and 22:6(n-3), and significant increase in the levels of monounsaturated fatty acids were observed in ovary during sexual maturation, which indicates these compounds as the major sources of energy during embryonic and early larval development.

Reproductive biology and endocrinology of female red gurnard, Chelidonichthys kumu (Lesson and Garnot) (family Triglidae), from the Hauraki Gulf, New Zealand

1994 ◽  
Vol 45 (2) ◽  
pp. 131 ◽  
Author(s):  
SJ Clearwater ◽  
NW Pankhurst
Keyword(s):  
New Zealand ◽  
Ovarian Development ◽  
Gonadosomatic Index ◽  
Plasma Concentrations ◽  
Early Summer ◽  
Spawning Season ◽  
Hepatosomatic Index ◽  
Fish Processing ◽  
North Eastern ◽  
Gonadal Recrudescence

Red gurnard, Chelidonichthys kumu, were sampled by long-lining and from a fish processing factory to investigate the seasonal cycle of reproduction in a population from north-eastern New Zealand. Female red gurnard showed changes in gonadosomatic index (GSI) and frequencies of stages of ovarian development consistent with spawning from spring (September) until autumn (May). Peak GSI (approximately 6%) occurred in late spring or early summer, and minimum GSI (approximately 1%) occurred in winter (June). Blood samples were taken from live fish caught on long-lines, and seasonal changes in plasma concentrations of oestradiol-17� (E2) and testosterone (T) were measured by radioimmunoassay. Plasma E2 and T reached maximum concentrations of 1.99 ng mL-1 and 2.06 ng mL-1, respectively, as GSI levels peaked, and then declined as GSI decreased over summer. Plasma E2 and T increased again as GSI began to increase prior to the next spawning season. Maximum hepatosomatic index (HSI) occurred in association with gonadal recrudescence. HSI decreased significantly as the spawning season progressed and showed a significant but irregular increase as recrudescence occurred prior to the following spawning season.

scholarly journals The length-weight relationship, condition factor and reproductive biology of Pseudotolithus (p) senegalensis (valenciennes, 1833) (croakers), in Tombo western rural district of Sierra Leone

2014 ◽  
Vol 14 (66) ◽  
pp. 9376-9389
Author(s):  
JO Olapade ◽  
◽  
S Tarawallie
Keyword(s):  
Sex Ratio ◽  
Sierra Leone ◽  
Reproductive Biology ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Hepatosomatic Index ◽  
Allometric Growth ◽  
Spawning Period ◽  
Weight Relationship ◽  
Spawning Behaviour

The length – weight relationship (LWR), condition factor (K), sex ratio, gonadosomatic index (G S I) and hepatosomatic index (H S I) of 412 specimens of Pseudotolithu s s enegalensis (Valenciennes, 1833) from Tombo , a coastal fishing community in the western rural district of Sierra Leone were studied for twelve months . Samples used for the study were collected from the catches of artisanal fishers and measurement s of length and weight of samples were done in situ using the facilities of the Ministry of Fisheries and Marine Resources. Samples for the reproductive study were preserved in an ice box and taken to the laboratory of the Department of Aquaculture and Fisheries Management, Njala University , Sierra Leone for analysis. The parameters "a" and "b" of the length - weight relationship were estimated using the equation described by Ricker ( W = aL b ) while the condition factor was calculated using Fulton`s equation (K = W1 00 / L 3 ) . The reproductive biology of the fish was estimated using Gonadosomatic index ( GSI ) and Hepatosomatic index ( H S I ) . The combined LWR for both sexes showed that a, b and r values were – 2.57 , 3. 3 5 and 0. 899 , respectively. The r – values obtained show a strong linear relationship between the length and weight of the species. The length - weight relationship indicated allometric growth for P . senegalensis in the study area. The condition factor (K) varied from 0.64 – 1.0 ; this may be attributed to environmental conditions of the water . The species clearly exhibited a positive allometric growth pattern ( tα ( 2) , 0.05, 411 > 1.965) . The sex ratio of males to females was 1:1. 15 and was not significantly different from the expected 1:1 ratio. Estimation of GSI and HSI was carried out from December, 2010 to May, 2011 to determine the spawning behaviour of P. senegalensis . The mean GSI obtained indicate d that March and April , respectively are the two peak spawning period for the species . Gonado somatic index ranged between 1.1 % and 2.8% for the females. The results of this study revealed that P. senegalensis doe s not have obligatory spawning month but exhibit multiple spawning behaviour. T he length - w eight relationships and condition factor of the study indicated that the fish were thriving very well in the coastal water of Sierra Leone. Sustainable management of the species , therefore , require s that the environment be protected against anthropogenic pollution and imposition of closed fishing season especially during the t wo peak spawning period is recommended to enable the species recruit effectively.

Plasma concentrations of testosterone and luteinizing hormone in rutting reindeer bulls (Rangifer tarandrus)

1980 ◽  
Vol 58 (11) ◽  
pp. 2081-2083 ◽  
Author(s):  
K.-A. Stokkan ◽  
K. Hove ◽  
W. R. Carr
Keyword(s):  
Luteinizing Hormone ◽  
Testosterone Level ◽  
Plasma Concentrations ◽  
Plasma Testosterone ◽  
Plasma Samples ◽  
Diurnal Pattern ◽  
Testosterone Concentration ◽  
Peripheral Plasma ◽  
The Mean

Concentrations of plasma testosterone and luteinizing hormone (LH) were measured in peripheral plasma from semidomestic, rutting reindeer bulls. Although the concentrations of plasma testosterone were high and showed large variations, those of LH were low and only a few episodic bursts could be detected in hourly samples taken throughout a 48-h period. The mean testosterone concentration in three bulls differed significantly and ranked the animals according to their position in a fighting hierarchy. The mean concentrations of LH did not differ significantly. Plasma samples from one reindeer bull sampled every 20 min for periods of 3 h indicated that an increment in LH concentration preceded a peak in testosterone. No diurnal pattern in testosterone concentrations could be detected, but testosterone peaks seemed to appear about every 3–4 h. The present study thus demonstrates that a series of plasma samples throughout the day is necessary to determine a true "testosterone level" in the reindeer bull.

The reproductive cycle of the smooth skate, Malacoraja senta, in the Gulf of Maine

2007 ◽  
Vol 58 (1) ◽  
pp. 98 ◽  
Author(s):  
James A. Sulikowski ◽  
Scott Elzey ◽  
Jeff Kneebone ◽  
Joe Jurek ◽  
W. Huntting Howell ◽  
...  
Keyword(s):  
Reproductive Cycle ◽  
Gulf Of Maine ◽  
Gonadosomatic Index ◽  
Management Plan ◽  
Biological Data ◽  
Hepatosomatic Index ◽  
Reproductive Parameters ◽  
Western Atlantic ◽  
The North ◽  
Gland Weight

The smooth skate (Malacoraja senta) is a small species of skate that is native to the waters of the north-western Atlantic. Recent assessments in the Gulf of Maine indicate that the biomass of smooth skates has declined below threshold levels mandated by the Sustainable Fisheries Act. This decline, coupled with the paucity of biological data, has prompted the National Marine Fisheries Service to prohibit the possession of smooth skates in this region. Consequently, crucial life history information is now being collected, which could be used in the formulation of a management plan. The present study describes and characterises the reproductive cycle of female and male smooth skates, based on monthly samples taken off the coast of New Hampshire, USA, from May 2001 to April 2002. Gonadosomatic index (GSI), hepatosomatic index (HSI), shell gland weight, follicle size and egg case formation were assessed for 79 female skates. In general, these reproductive parameters remained relatively constant throughout most of the year. Additionally, the size distribution of ovarian follicles in females captured each month did not vary significantly. For males (n = 81), histological stages of spermatogenesis III to VI (SIII-SVI), GSI and HSI were examined. No significant differences were detected in male reproductive parameters, and production and maintenance of mature spermatocysts within the testes were observed throughout the year. Collectively, these findings indicate that, like other north Atlantic skate species, the smooth skate is reproductively active year-round.

Reproductive biology of four Diplodus species Diplodus vulgaris, D. annularis, D. sargus sargus and D. puntazzo (Sparidae) in the Gulf of Tunis (central Mediterranean)

2011 ◽  
Vol 92 (3) ◽  
pp. 623-631 ◽  
Author(s):  
N. Mouine ◽  
P. Francour ◽  
M.H. Ktari ◽  
N. Chakroun-Marzouk
Keyword(s):  
Gonadosomatic Index ◽  
Spawning Season ◽  
Sexual Cycle ◽  
Hepatosomatic Index ◽  
Central Mediterranean ◽  
Important Species ◽  
Spawning Period ◽  
Gulf Of Tunis ◽  
Sharpsnout Seabream ◽  
First Maturity

The reproductive features of four commercially important species of the Diplodus genus were studied in the Gulf of Tunis to contribute to better fisheries management on the local scale. The study was specifically aimed to estimate sex-ratio and size at first maturity, to determine spawning season, to analyse hepatic and muscular energy reserve changes and to highlight possible regional difference over the Diplodus geographical distribution. A total of 570 Diplodus vulgaris (two-banded seabream), 428 Diplodus annularis (annular seabream), 350 Diplodus sargus sargus (white seabream) and 218 Diplodus puntazzo (sharpsnout seabream) were collected from the commercial catches of the artisanal fleet between October 2004 and June 2006. Male:female ratio was initially skewed in favour of females for the four Diplodus species and especially among larger-sized individuals. Length and age at first maturity was 17.4 ± 0.2 cm total length (TL) (4 years) for D. vulgaris, 9.7 cm TL (2 years) for D. annularis, 21.0 ± 0.3 cm TL (4 years) for D. s. sargus, 21.5 ± 0.2 cm TL (3 years) for D. puntazzo and a recommendation is made for the increasing of the captured length. According to the monthly succession of gonad maturity stages and the yearly gonadosomatic index (GSI) fluctuation, the spawning season of Diplodus species present a temporal succession along the year. The two-banded seabream has a winter spawning period, the white seabream is mainly a spring spawner, the annular seabream spawns essentially in summer months and the spawning of sharpsnout seabream takes place in autumn. Generally, hepatosomatic index presented an inverse trend to GSI in relation to the breeding activity. The condition factor showed significant monthly variations affected by the sexual cycle of the Diplodus species.

Annual change in reproductive condition and plasma concentrations of sex steroids in black bream, Acanthopagrus butcheri (Munro) (Sparidae)

1998 ◽  
Vol 49 (5) ◽  
pp. 389 ◽  
Author(s):  
J. A. Haddy ◽  
N. W. Pankhurst
Keyword(s):  
Sex Steroids ◽  
Gonadosomatic Index ◽  
Plasma Concentrations ◽  
Early Morning ◽  
Early Summer ◽  
Hepatosomatic Index ◽  
Black Bream ◽  
One Year ◽  
Gonad Condition ◽  
Acanthopagrus Butcheri

Changes in gonadosomatic index (GSI), hepatosomatic index (HSI), gonad stage and plasma concentrations of sex steroids were studied over one year in black bream (Acanthopagrus butcheri). Black bream have an annual reproductive cycle with a 3-month spawning season in spring–early summer. GSI and HSI values were highest in October and May respectively. Plasma concentrations of oestradiol-17β (E2), testosterone (T) and 17,20β-dihydroxy-4-pregnen-3-one (17,20βP) were highest in females in October. Plasma concentrations of E2 and T were highest in ovulated fish. Concentrations of 17,20βP were higher in fish undergoing final oocyte maturation (FOM) than in fish with regressed gonads. In males, plasma concentrations of T and 11-ketotestosterone (11KT) increased in September and remained elevated until January, but concentrations of 17,20βP did not change with season. However, 17,20βP concentrations in spermiated fish were higher than in non-spermiated fish. Daily changes in gonad condition indicated that females undergo daily cycles of ovarian maturation with ovulation occurring after midday. Plasma T and 17,20βP concentrations of females were elevated at midday in association with FOM, but E2 showed no diel change. In males, partially spermiated fish were dominant in the early morning and fully spermiated fish at midday. Plasma T, 11KT and 17,20βP concentrations were low at midnight and reached maximum levels at 0600 hours.

scholarly journals Seasonal analysis of condition, biochemical and bioenergetic indices of females of Brazilian flathead, Percophis brasiliensis

2013 ◽  
Vol 11 (1) ◽  
pp. 153-162 ◽  
Author(s):  
Karina A. Rodrigues ◽  
Gustavo J. Macchi ◽  
Agueda Massa ◽  
María I. Militelli
Keyword(s):  
Energy Density ◽  
Reproductive Cycle ◽  
Biochemical Composition ◽  
Seasonal Pattern ◽  
Gonadosomatic Index ◽  
Energy Allocation ◽  
Reproductive Period ◽  
Spawning Period ◽  
Different Tissues ◽  
Percophis Brasiliensis

Percophis brasiliensis is a demersal species that constitutes an important resource of Argentine coastal fisheries. Nevertheless, information about bioenergetic dynamic of reproduction has not been reported. Therefore, seasonal variations of condition factors, biochemical composition and energy density of different tissues were analyzed in order to determine the strategy of energy allocation during the reproductive cycle of this species. Condition indices (hepatosomatic and K) showed a seasonal pattern opposite to that observed for gonadosomatic index, which was characterized by higher values during the reproductive period (spring-summer), decreasing at the end of spawning. Biochemical composition of different tissues also showed a clearly seasonality associated to reproductive cycle. Analysis of energy density variation of liver indicates that P. brasiliensis accumulate reserves in winter before reproduction, which later decrease during the spawning season. In contrast, the energy density in muscle did not show significant differences among seasons, indicating that individuals could be also using an external source of energy during spawning. Therefore, it is possible that P. brasiliensis respond to an intermediate strategy of energy allocation, combining characteristics of both capital breeders (stores energy previous to the onset of reproductive activity) and income breeders (acquire energy by active feeding during spawning period).

Sign in / Sign up

Export Citation Format

Share Document