Temperature induces gonadal maturation and affects electrophysiological sexual maturity indicators in Brachyhypopomus pinnicaudatus from a temperate climate

L. Quintana

doi:10.1242/jeb.00954

Reproductive biology of the land crab Cardisoma guanhumi (Decapoda: Gecarcinidae) in north-eastern Brazil

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315412000951 ◽

2012 ◽

Vol 93 (3) ◽

pp. 761-768 ◽

Cited By ~ 4

Author(s):

Renata Akemi Shinozaki-Mendes ◽

José Roberto Feitosa Silva ◽

Jones Santander-Neto ◽

Fábio Hissa Vieira Hazin

Keyword(s):

Sexual Maturity ◽

Histological Analysis ◽

Carapace Width ◽

Gonadal Maturation ◽

Land Crab ◽

Eastern Brazil ◽

North Eastern ◽

Cardisoma Guanhumi ◽

Maturation Stages ◽

First Maturity

The reproductive cycle of Cardisoma guanhumi was described from the analysis of seasonal variation of the gonadal maturation stages. The first maturity for both sexes was determined based on three different tests: inflexion point on the curve; relevant character (morphometry); and histological analysis (physiology). In addition, some aspects of sexual dimorphism for the population were studied. A total of 353 individuals caught in north-eastern Brazil between December 2006 and November 2007 were analysed. The sex-ratio was statistically equal (P ≥ 0.05) and the carapace width (CW) of the females ranged from 4.34 to 8.56 cm and of the males from 2.84 to 9.22 cm. Mature females with fully developed gonads begin to appear in the dry season (August) and ovigerous females occurred from November to February, suggesting that spawning occurs mainly during the rainy season. The CW of first sexual maturity for females ranged from 5.87 cm to 6.70 cm and males from 6.22 cm to 7.20 cm. The highest percentage of individuals caught were juveniles, indicating the need for a targeted effort to preserve the species.

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Asynchronous spermatogenesis and biennial female cycle of the viviparous lizard Phymaturus antofagastensis (Liolaemidae): reproductive responses to high altitudes and temperate climate of Catamarca, Argentina

Amphibia-Reptilia ◽

10.1163/156853806776052119 ◽

2006 ◽

Vol 27 (1) ◽

pp. 25-36 ◽

Cited By ~ 21

Author(s):

Nora Ibargüengoytía ◽

Jorgelina Boretto

Keyword(s):

Reproductive Cycle ◽

Sexual Maturity ◽

Late Summer ◽

Thermal Fluctuations ◽

Operational Sex Ratio ◽

Temperate Climate ◽

Head Width ◽

Adult Males ◽

Males And Females ◽

Reproductive Cycles

AbstractThis paper studies minimum SVL at sexual maturity, sexual dimorphism, operational sex ratio, male and female reproductive cycles, and litter size of viviparous Phymaturus antofagastensis, a species living at high altitude in the temperate climate of Catamarca, Argentina. Males reached sexual maturity at 90 mm, and females at 79 mm. Adult males attained significantly larger body size and head width than adult females. Histological analysis showed asynchrony in spermatogenesis timing among males and spermatozoa storage in epididymis throughout the reproductive season (spring to early autumn). Females showed a biennial reproductive cycle taking at least one activity season to perform either vitellogenesis or pregnancy. Brood size resulted in two offspring, a condition similar to other species of the genus, with births occurring in late summer. The reproductive cycle of Phymaturus antofagastensis shows a new response in males and females to harsh environments characterized by short activity seasons, long hibernation periods and large daily and seasonal thermal fluctuations.

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Temporal Dynamics of Reproduction of the Neotropical Fish,Crenicichla menezesi(Perciformes: Cichlidae)

The Scientific World JOURNAL ◽

10.1100/2012/579051 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 5

Author(s):

Andréa Soares de Araújo ◽

Wallace Silva do Nascimento ◽

Maria Emília Yamamoto ◽

Sathyabama Chellappa

Keyword(s):

Sexual Maturity ◽

Temporal Dynamics ◽

Condition Factor ◽

Cichlid Fish ◽

Gonadal Development ◽

Neotropical Fish ◽

Spawning Period ◽

Gonadal Maturation ◽

Development Cycle ◽

Partial Spawner

The reproductive biology and the gonadal development cycle of the Neotropical cichlid fish,Crenicichla menezesi, is described. This species exhibits sexual dimorphism only during the spawning season. First sexual maturity of females is attained earlier than the males. Both macroscopic and histological investigations of ovaries and testes revealed four stages of gonadal maturation. Mean batch fecundity of females was 372 (±10,41) of mature oocytes. This species is a partial spawner, with an extended spawning period. Monthly values of GSI and the condition factor are negatively correlated during the gonadal development cycle of this species.

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Growth in a cold environment: body size and sexual maturity in a northern population of spotted turtles, Clemmys guttata

Canadian Journal of Zoology ◽

10.1139/z98-002 ◽

1998 ◽

Vol 76 (5) ◽

pp. 773-782 ◽

Cited By ~ 7

Author(s):

Jacqueline D Litzgus ◽

Ronald J Brooks

Keyword(s):

Growth Rate ◽

Body Size ◽

Growth Rates ◽

Sexual Maturity ◽

Carapace Length ◽

Temperate Climate ◽

Von Bertalanffy ◽

Adult Body Size ◽

Clemmys Guttata ◽

Adult Body

Using mark-recapture data collected from 1978 to 1997, we examined growth rates, adult body size, and age and size at sexual maturity of spotted turtles (Clemmys guttata) in a northern temperate climate. Relative instantaneous growth rate analyses indicated that growth rates were inversely related to body size, individual variation in growth rate was high, and females and males did not differ with respect to growth rates. Growth of our spotted turtles was described well by both the von Bertalanffy and logistic growth models, although the von Bertalanffy model provided a slightly better fit to our data. Asymptotic sizes and intrinsic growth factors did not differ between the sexes. Northern spotted turtles reach a larger mean adult body size relative to southern populations. Turtles were not sexually size dimorphic with respect to carapace length; however, plastron length was greater in females than in males. Sexual maturity was reached at a larger size (a carapace length of approximately 103 mm for females and 105 mm for males) and estimated age (12-15 years for females and 11-13 years for males) in northern spotted turtles relative to more southerly conspecifics.

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THE »EARLY-ANDROGEN« SYNDROME; ITS DEVELOPMENT AND THE RESPONSE TO HEMI-SPAYING

Acta Endocrinologica ◽

10.1530/acta.0.0450001 ◽

1964 ◽

Vol 45 (1) ◽

pp. 1-12 ◽

Cited By ~ 46

Author(s):

H. E. Swanson ◽

J. J. van der Werff ten Bosch

Keyword(s):

Sexual Maturity ◽

Compensatory Growth ◽

Testosterone Propionate ◽

Single Injection ◽

Weight Increase ◽

Corpora Lutea ◽

Transition Stage ◽

Adult Females

ABSTRACT The »early-androgen« syndrome in the rat – i. e. anovulatory ovaries in adult females after a single injection of testosterone propionate (TP) within a week of birth – may not become apparent until some time after the attainment of sexual maturity. Large doses (50 or 100 μg) of TP were effective earlier than lower doses (5 or 10 μg). Rats which received 5 μg TP were ovulating at 10 weeks of age, mated but were infertile at 13 weeks of age, and were anovulatory at 21 weeks. In rats between 10 and 13 weeks old there was a marked fall in the number of corpora lutea in the ovaries of animals which had been given 5 μg TP. Hemi-spaying was followed by compensatory growth of the remaining ovary which consisted of corpora lutea in ovulating, and of follicles in anovulatory rats; little or no compensatory weight increase occurred in animals which seemed to be in the transition stage from the ovulatory to the anovulatory condition.

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