Monthly variations in the profile of sex steroids and gonadal development of brook trout (Salvelinus fontinalis Mitchill) during puberty in Tasmania

2014 ◽  
Vol 62 (3) ◽  
pp. 200 ◽  
Author(s):  
Shafaq Fatima ◽  
Mark Adams ◽  
Ryan Wilkinson
Keyword(s):  
Sex Steroids ◽  
Brook Trout ◽  
Ovarian Development ◽  
Salvelinus Fontinalis ◽  
Gonadosomatic Index ◽  
Gonadal Development ◽  
First Year ◽  
Female Fish ◽  
Oocyte Stage ◽  
Monthly Variations

Puberty is an important reproductive event that has not been studied in brook trout in the Southern Hemisphere. The present study describes the histological development of gonads and variations in the levels of oestradiol-17β (E2), testosterone (T) and 11-ketotestosterone (11-KT) during the first year of male and female brook trout. The study started when the trout were at an age of 8 months (n = 10) and continued until they were 15 months. Of the males, 60% attained puberty at an age of 14 months. The peak of the gonadosomatic index in males was observed at 15 months of age (3.0 ± 0.9%). Female fish did not achieve maturation during their first year and ovarian development did not progress beyond the vesicular oocyte stage within the study period.

Monthly variations in the profile of sex steroids and ovarian development of brook trout (Salvelinus fontinalis Mitchill) during the annual reproductive cycle in Tasmania

2015 ◽  
Vol 63 (3) ◽  
pp. 220 ◽  
Author(s):  
Shafaq Fatima ◽  
Mark Adams ◽  
Ryan Wilkinson
Keyword(s):  
Reproductive Cycle ◽  
Sex Steroids ◽  
Brook Trout ◽  
Ovarian Development ◽  
Gonadosomatic Index ◽  
Annual Reproductive Cycle ◽  
Total Fecundity ◽  
Mature Fish ◽  
Index Value ◽  
Monthly Variations

Control of maturation in all-female salmonid stock can be achieved by manipulating photoperiod. This initially requires an assessment of the annual reproductive cycle under ambient photoperiod. This study therefore describes the seasonal variations in ovarian development and plasma profiles of oestradiol-17β and testosterone during the second year of a population of female brook trout. It was found that fish recruited for maturation following the summer solstice in December. Shortening of photoperiod likely stimulated the brain–pituitary–gonadal axis for vigorous progress of ovarian development, as indicated by increasing levels of oestradiol-17β and gonadosomatic index values. The highest gonadosomatic index value (18.26 ± 1.1%) was observed in June. During July, eggs were released from mature females by manual stripping. Total fecundity was observed as 4266 ± 341 oocytes per mature fish. Profiles of sex steroids observed here were found to be finely entrained within the succession of seasonal photoperiod. This finding indicates that maturation suppression by photoperiod manipulation should be instigated before initiation of oocyte recruitment that commenced during December.

Influence of Light and Temperature on the Reproductive Cycle of the Eastern Brook Trout, Salvelinus fontinalis (Mitchill)

1963 ◽  
Vol 20 (4) ◽  
pp. 859-897 ◽  
Author(s):  
Nancy E. Henderson
Keyword(s):  
Environmental Factors ◽  
Seasonal Changes ◽  
Brook Trout ◽  
Ovarian Development ◽  
Salvelinus Fontinalis ◽  
Average Diameter ◽  
Gonadal Development ◽  
Light Regime ◽  
Male And Female ◽  
First Time

Brook trout were exposed to photoperiods ranging from 4 to 20 hours per day and were held either at 8.5 °C or at 16°. The average diameter of the ova was used as an index of ovarian development while testicular maturation was determined from histological preparations.The gonadal cycles of both male and female trout were markedly affected by different photoperiodic regimes. The influence of long or short photoperiods depends upon the phase of gametogenesis in progress at the time and on the photoperiod in effect during earlier stages of the gonadal cycle. Evidence is presented which suggests that the maturation cycle of the gonads may be regulated by the normal seasonal changes of day length.An accelerated light regime can hasten the time of functional maturity in adult trout, but is without effect when applied to maturing fish in which gametogenesis is taking place for the first time. It is suggested that a stimulative effect of environmental factors is dependent upon maturation of the hypothalamic-hypophyseal mechanism.The rate of gonadal development is the same at 16° as it is at 8.5° provided the fish are exposed to natural day lengths. If fish are subjected to long or to short photoperiods, the gonadal response at 16° is quite different from that at 8.5°.

Differences in sexual maturity and fall emigration between diploid and triploid brook trout (Salvelinus fontinalis) in an Adirondack lake

1997 ◽  
Vol 54 (8) ◽  
pp. 1808-1812 ◽  
Author(s):  
J A Warrillow ◽  
D C Josephson ◽  
W D Youngs ◽  
C C Krueger
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Gonadal Development ◽  
Spawning Habitat ◽  
Diploid Males ◽  
Reproductive Risk ◽  
Spawning Areas ◽  
In Captivity ◽  
Adirondack Lakes ◽  
Triploid Fish

High levels of emigration coincident with maturity and spawning have been reported from brook trout (Salvelinus fontinalis) populations in Adirondack lakes. These lakes typically had few spawning areas and required stocking to maintain populations. We compared diploid and triploid brook trout to identify differences in gonadal development and emigration. Age 1 + and 2 + diploid and triploid brook trout held in captivity were examined internally for gonadal development. More diploid trout were mature than triploid fish (p < 0.01). Of triploid brook trout that matured, all were males. Yearling diploid and triploid brook trout were also stocked into a lake that had an outlet but no spawning areas. During the fall spawning season, only mature yearling triploid males, diploid males, and diploid females were caught in an outlet trap. No triploid females were caught. A greater proportion of diploids emigrated than triploids (p < 0.01). Triploidy in females arrested emigration by preventing sexual maturation. Triploid male brook trout should not be stocked because they can pose a reproductive risk to wild brook trout downstream from lakes. Stocking triploid females could reducefall emigration and thus reduce the loss of catchable brook trout from Adirondack lakes with outlets and little spawning habitat.

Determination of Sexual Maturation Stages of Atlantic Salmon (Salmo salar) Captured at Sea

1981 ◽  
Vol 38 (4) ◽  
pp. 405-413 ◽  
Author(s):  
D. R. Idler ◽  
S. J. Hwang ◽  
L. W. Crim ◽  
D. Reddin
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Gonadosomatic Index ◽  
Gonadal Development ◽  
Maturation Stage ◽  
Female Fish ◽  
Histological Techniques ◽  
Atlantic Salmon Salmo Salar ◽  
Placentia Bay

Radioimmunoassay (RIA) of plasma vitellogenin (Vg), estradiol (E2), 11-ketotestosterone (11-keto), and gonadotropin (GtH), together with histological techniques were evaluated for determination of the maturation stage of Atlantic salmon (Salmo salar) at sea.Male salmon had lower plasma Vg, E2, and higher 11-keto levels and could be distinguished from females several months in advance of spawning. Six female salmon were tagged at sea in 1975 in Placentia Bay and samples of blood taken. When the fish were recovered in rivers the lowest plasma Vg value was 396 μg/mL. This formed the basis of a working hypothesis, that fish with Vg values in excess of 396 μg/mL (~5–6 mo before spawning) will spawn in the year of capture. This hypothesis was supported by the Vg values of an additional 19 tagged females recaptured in Newfoundland and mainland rivers and brackish water off mainland rivers in 1976.Significant correlations between stage of gonadal development and plasma Vg, stage of gonadal development and gonadosomatic index (GSI), stage of gonadal development and plasma E2, plasma Vg and plasma E2, GSI and plasma E2, and between plasma Vg and 11-keto values were found for the female fish. The gonadal development of female fish from Bonavista Bay ranged between oil globule stage and secondary yolk stage. All those females which had reached the primary yolk stage would almost certainly mature and may be considered spawners of the year; on this basis 91% of the females were spawners of the year. Based on the minimum plasma Vg values, at sea, for fish which subsequently returned to the rivers, there were 86% spawners of the year among female salmon taken in Bonavista Bay. Based on plasma Vg levels, spawners of the year ranged from essentially zero in Greenland (fish captured in Greenland during August–November are not spawners of the year, except for the very few that spawn in one Greenland river) to 100% for fish caught in several other fisheries.11-Ketotestosterone was higher in the male fish than in the female fish and there was a correlation between GSI and 11-keto for male fish.The plasma GtH content of fish taken in the sea was extremely low as measured by RIA.Key words: salmon, maturation, migration, radioimmunoassay, vitellogenin, estradiol, gonadotropin, 11-ketotestosterone, histology, gonadosomatic index

scholarly journals Comparative Analysis of Pejerrey Fish (Odontesthes bonariensis) Gonadal Development During Two Consecutive Spawning Seasons in Relation to Sex Steroids and Temperature Variation in Cochicó Lake (Pampas Region, Argentina)

2021 ◽  
Vol 21 (07) ◽  
pp. 347-355
Author(s):  
Pamela Sabrina del Fresno ◽  
Darío César Colautti ◽  
Gustavo Emilio Berasain ◽  
Leandro Andrés Miranda
Keyword(s):  
Sex Steroids ◽  
Gonadosomatic Index ◽  
Gonadal Development ◽  
Sexual Steroids ◽  
Odontesthes Bonariensis ◽  
Intensive Use ◽  
Game Fish ◽  
First Time ◽  
Pampas Region

Cochicó belongs to “Encadenadas del Oeste” system of lakes being a typical water body of the Pampas region. The most abundant fish species in this lake is the pejerrey (Odontesthes bonariensis) valued due to the quality of its flesh and as a game fish. The aim of this study was to compare the gonadal stages of pejerrey during two consecutive spawning seasons (August to December) in relation to sexual steroids and temperature in this lake. In general, pejerrey gonadal development, the Gonadosomatic index and the plasma levels of estradiol and testosterone fluctuated in relation with temperature. In 2014 samplings, females started to ovulating in early August, with a peak during September-October and ending in December with many of them with atretic oocytes. However, in 2015, a marked delay in maturation was observed with ovulated fish only in October and December. This fact may be because the minors mean temperatures recorded in this year. For males, it was possible to find spermiating animals during the whole spawning season and only arrested animals in December. Unexpectedly, histological gonadal analysis revealed for the first time pejerrey with testis-ova, probably due to the intensive use of agrochemicals in this region.

Impact of Brook Trout (Salvelinus fontinalis) Predation on the Crayfish Orconectes virilis in Three Michigan Lakes

1979 ◽  
Vol 36 (10) ◽  
pp. 1191-1196 ◽  
Author(s):  
H. Gowing ◽  
W. T. Momot
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
First Year ◽  
Orconectes Virilis ◽  
Trout Population ◽  
Production Growth ◽  
First Year Of Life ◽  
The Cost ◽  
Slow Growing ◽  
Northern Michigan

The crayfish Orconectes virilis is a major component of the benthos of three small lakes in northern Michigan. These lakes contained stocked brook trout (Salvelinus fontinalis) populations (age-0 and age-I) at densities of 188, 411, and 1398 fish/ha. Crayfish were preyed upon by brook trout, but only during their first year of life. Two-year production of age-0 crayfish was approximately 94 kg in each lake; brook trout consumed only about 1–2% in lakes with lower density offish. Even with greater trout density and accompanying higher rate of exploitation (40%), there was no impact on recruitment of young crayfish because compensatory mortality of crayfish occurred in lakes with less trout predation. However, stocking trout at higher densities decreased trout growth and condition. While 2-yr production was highest (59 kg/ha) in the lake stocked at the highest density and lowest (17 kg/ha) in one stocked at the lowest density, the former was achieved at the cost of a very slow growing trout population. Most of the crayfish production is not utilized as trout food but enters the non-predatory pool of detrital organic matter. Key words: Orconectes virilis, brook trout, predation, production growth, mortality

In situ survival and growth of three brook trout (Salvelinus fontinalis) strains subjected to acid conditions of anthropogenic origin at the egg and fingerling stages

2000 ◽  
Vol 57 (8) ◽  
pp. 1562-1573 ◽  
Author(s):  
Stephanie Lachance ◽  
Pierre Bérubé ◽  
Michel Lemieux
Keyword(s):  
Brook Trout ◽  
Natural Waters ◽  
Salvelinus Fontinalis ◽  
Gonadosomatic Index ◽  
Anthropogenic Origin ◽  
Weight Yield ◽  
Acid Environment ◽  
Acid Tolerant ◽  
Chemical Conditions

Tolerance to naturally acidic conditions of a Côte-Nord brook trout (Salvelinus fontinalis) strain (Arseneault strain, presumed acid tolerant) does not appear completely genetically mediated, since this tolerance was not evident when the fish were subject to acid conditions of anthropogenic origin. Three wild brook trout strains, at the egg and fingerling stages, were exposed in the field to waters acidified by atmospheric deposition of anthropogenic origin as well as to natural waters typical of the region. Although egg mortality was significantly higher in acid (61.0-85.6%) than in reference (6.3-20.8%) conditions, no differences between strains were noted. Residual density 1 year after stocking with fingerlings was significantly higher (by 56%) in the reference lake than in the acid lake, but differences between strains did not follow any clear tendency. While overall growth was greater in the acid environment, weight yield was lower except for the Arseneault strain. Variations pertaining to gonadosomatic index and percent mature individuals in both males and females seemed linked more to differences in growth than to chemical conditions. Developing a permanent reintroduction program with the Arseneault strain to counter losses of brook trout populations due to acid precipitation in Québec does not appear justified at this time.

Sign in / Sign up

Export Citation Format

Share Document