Sexual maturity, molting, and reproductive activity in the Carib Grackle (Quiscalus lugubris)

2021 ◽  
Author(s):  
Luisa F. Saavedra ◽  
Yadi X. Figueroa ◽  
Víctor H. Serrano-Cardozo ◽  
Martha P. Ramírez-Pinilla
Keyword(s):  
Sexual Maturity ◽  
Reproductive Activity ◽  
Quiscalus Lugubris

Population dynamics of Sesarma rectum (Crustacea: Brachyura: Grapsidae) in the Ariquindá River mangrove, north-east of Brazil

2011 ◽  
Vol 91 (7) ◽  
pp. 1395-1401 ◽  
Author(s):  
Daniela da Silva Castiglioni ◽  
Paloma Joana Albuquerque de Oliveira ◽  
Josivan Soares da Silva ◽  
Petrônio Alves Coelho
Keyword(s):  
Sex Ratio ◽  
Sexual Maturity ◽  
Carapace Width ◽  
Reproductive Activity ◽  
Reproductive Period ◽  
Size Class ◽  
Adult Males ◽  
North East ◽  
Class Frequency ◽  
Autumn And Winter

This study was carried out in order to provide basic information on the population ecology of the crab Sesarma rectum in the Ariquindá River mangrove, Tamandaré, State of Pernambuco, Brazil. The population was analysed with regard to the following aspects, in particular: the size-class frequency distribution of carapace width (CW), mean body size (CW) of males and females, morphological sexual maturity, sex-ratio, reproductive period, and recruitment. Samples were collected monthly from April 2008 through to March 2009; the crabs were collected manually, with a capture effort by one person for 30 minutes, during low tide. The specimens obtained were measured for CW, length of the propodus of males, and abdomen width of females; and the sex and ovigerous condition were noted. Altogether, we obtained 511 specimens (132 juvenile and 137 adult males, and 171 juvenile and 71 adult females, of which 32 were ovigerous). The median CW of males (16.15 mm) was significantly larger than that of females (13.82 mm) (P < 0.05). The size at morphological sexual maturity was 15.73 mm in males and 16.71 mm in females. The sex-ratio for the total of specimens analysed was 1.11:1 (male:female) (P > 0.05). The sex-ratio by size-class showed an anomalous pattern, with a greater abundance of males in the larger size-classes. The reproductive period was continuous and the highest frequency of ovigerous females was recorded in the spring and summer. The major pulse of recruitment occurred during autumn and winter, which is related to greater reproductive activity during the warmer months of the year.

Observations on the reproduction and ecology of the Brush-tailed possum. Trichosurus Vulpecula Kerr (Marsupialia), in New Zealand.

1955 ◽  
Vol 3 (2) ◽  
pp. 162 ◽  
Author(s):  
CH Tyndale-Biscoe
Keyword(s):  
Sexual Maturity ◽  
Post Partum ◽  
Reproductive Activity ◽  
Urogenital Sinus ◽  
Trichosurus Vulpecula ◽  
Reproductive Condition ◽  
Age Classes ◽  
Adult Females ◽  
Epiphyseal Union ◽  
Cyclic Changes

In all 366 adult possums and 139 pouch young were examined. Five samples were collected and a study of a live population was conducted. Data are presented on the relationships of weight, tibia1 ossification, and sexual maturity, which indicate that two age classes can be distinguished in the fully grown animals on the basis of epiphyseal union of the tibia. Correlations between body weight, testis length, and the presence of sperm are presented for 53 males. The reproductive condition of 209 females was examined and successive observations were made on another eight. It is considered that Trichosurus is dioestrous and monovular. Pregnancy lasts between 15 and 24 days and is sometimes followed by a post-partum ovulation. Cyclic changes in the uterus and the urogenital sinus are described. The urogenital sinus exhibits marked cornification at oestrus, similar to the vagina of eutherian mammals. Anoestrus in February is followed by increasing reproductive activity in March. By the beginning of May, 90 per cent. of the adult females are pregnant or post-partum and the offspring is carried in the pouch until August or September. Some females may produce a second offspring in October. Some observations on the movements of individuals are presented.

scholarly journals Disruption of deiodinase type 2 in zebrafish disturbs male and female reproduction

2019 ◽  
Vol 241 (2) ◽  
pp. 111-123 ◽  
Author(s):  
Anne M Houbrechts ◽  
Jolien Van houcke ◽  
Veerle M Darras
Keyword(s):  
Sexual Maturity ◽  
Reproductive Function ◽  
Reproductive Activity ◽  
Reproductive Period ◽  
Biologically Active ◽  
Sex Steroid ◽  
Female Reproduction ◽  
Steroid Production ◽  
Offspring Production

Thyroid hormones are crucial mediators of many aspects of vertebrate life, including reproduction. The key player is the biologically active 3,5,3’-triiodothyronine (T3), whose local bio-availability is strictly regulated by deiodinase enzymes. Deiodinase type 2 (Dio2) is present in many tissues and is the main enzyme for local T3 production. To unravel its role in different physiological processes, we generated a mutant zebrafish line, completely lacking Dio2 activity. Here we focus on the reproductive phenotype studied at the level of offspring production, gametogenesis, functioning of the hypothalamic–pituitary–gonadal axis and sex steroid production. Homozygous Dio2-deficient zebrafish were hypothyroid, displayed a delay in sexual maturity and the duration of their reproductive period was substantially shortened. Fecundity and fertilization were also severely reduced. Gamete counts pointed to a delay in oogenesis at onset of sexual maturity and later on to an accumulation of oocytes in mutant ovaries due to inhibition of ovulation. Analysis of spermatogenesis showed a strongly decreased number of spermatogonia A at onset of sexual maturity. Investigation of the hypothalamic–pituitary–gonadal axis revealed that dysregulation was largely confined to the gonads with significant upregulation of igf3, and a strong decrease in sex steroid production concomitant with alterations in gene expression in steroidogenesis/steroid signaling pathways. Rescue of the phenotype by T3 supplementation starting at 4 weeks resulted in normalization of reproductive activity in both sexes. The combined results show that reproductive function in mutants is severely hampered in both sexes, thereby linking the loss of Dio2 activity and the resulting hypothyroidism to reproductive dysfunction.

Reproduction in Captive Wallaroos - the Eastern Wallaroo, Macropus-Robustus-Robustus, the Euro, Macropus-Robustus-Erubescens and the Antilopine Wallaroo, Macropus-Antilopinus

1987 ◽  
Vol 14 (3) ◽  
pp. 225 ◽  
Author(s):  
WE Poole ◽  
JC Merchant
Keyword(s):  
Sexual Maturity ◽  
Post Partum ◽  
Reproductive Activity ◽  
Oestrous Cycle ◽  
Full Length ◽  
Reproductive Patterns ◽  
In Captivity

Wallaroos were bred in captivity during almost 20 years. Individual males attained sexual maturity at between 18 and 20 months old and females at between 14 and 24 months old; both sexes were capable of breeding throughout the year. Gestation was 30-38 d and extended almost the full length of the oestrous cycle, 31-46 d. Post-partum mating usually produced a blastocyst subject to lactational quiescence. Removal or loss of a pouch young usually resulted in birth 28-32 d later but up to 41 d later in the presence of an actively suckled young-at-foot. Pouch life ranged between 231 and 270 d, with vacation of the pouch usually followed by another birth 1-14 d later. Lactation exceeded 12-14 months but suckling had waned by 15-17 months. Reproductive patterns for M. r. robustus and M. r. erubescens were similar although significant differences between the subspecies were recorded in length of oestrous cycle, the interval from loss of pouch young to birth and post-partum oestrus, the length of pouch life and the time between vacation of the pouch and birth. In addition, the reproductive activity of hybrids produced by matings between the subspecies was observed, as was that of a limited number of M. antilopinus.

Reproducción de Psammodromus hispanicus en una arenal costero del nordeste ibérico

1991 ◽  
Vol 12 (4) ◽  
pp. 395-408 ◽  
Author(s):  
G.A. Llorente ◽  
M.A. Carretero
Keyword(s):  
Clutch Size ◽  
Temperature Increase ◽  
Sexual Maturity ◽  
Reproductive Activity ◽  
Endogenous Rhythm ◽  
Spring Temperature ◽  
Coastal Sand ◽  
Second Clutch ◽  
Ne Spain

Abstract; The reproduction of a population of Psammodromus hispanicus was studied on a coastal sand area of NE Spain and compared with other populations. Sexual maturity is reached in the first spring, and there are no subadults. Reproductive activity occurs in March to July. The beginning of reproduction depends on the spring temperature increase but the end is produced by an endogenous rhythm. Eggs size, clutch size and length of the hatchlings are very close to those of other populations. The major difference is that a second clutch can be laid by the largest females. This is the first such record in the species.

scholarly journals Growth patterns in brooding dinosaurs reveals the timing of sexual maturity in non-avian dinosaurs and genesis of the avian condition

2007 ◽  
Vol 3 (5) ◽  
pp. 558-561 ◽  
Author(s):  
Gregory M Erickson ◽  
Kristina Curry Rogers ◽  
David J Varricchio ◽  
Mark A Norell ◽  
Xing Xu
Keyword(s):  
Sexual Maturation ◽  
Sexual Maturity ◽  
Reproductive Activity ◽  
Growth Patterns ◽  
The Other ◽  
Growth Line ◽  
Adult Size ◽  
Secondary Sexual Characteristics ◽  
Sexual Characteristics ◽  
Population Sizes

The timing of sexual maturation in non-avian dinosaurs is not known. In extant squamates and crocodilians it occurs in conjunction with the initial slowing of growth rates as adult size is approached. In birds (living dinosaurs) on the other hand, reproductive activity begins well after somatic maturity. Here we used growth line counts and spacing in all of the known brooding non-avian dinosaurs to determine the stages of development when they perished. It was revealed that sexual maturation occurred well before full adult size was reached—the primitive reptilian condition. In this sense, the life history and physiology of non-avian dinosaurs was not like that of modern birds. Palaeobiological ramifications of these findings include the potential to deduce reproductive lifespan, fecundity and reproductive population sizes in non-avian dinosaurs, as well as aid in the identification of secondary sexual characteristics.

Reproduction in Sminthopsis-Macroura (Marsupialia, Dasyuridae) .2. The Male

1990 ◽  
Vol 38 (2) ◽  
pp. 207 ◽  
Author(s):  
PA Woolley
Keyword(s):  
Breeding Season ◽  
Sexual Maturity ◽  
Binding Capacity ◽  
Reproductive Activity ◽  
Reproductive Organs ◽  
Histological Changes ◽  
Accessory Glands ◽  
Sminthopsis Macroura ◽  
Sexually Mature ◽  
Androgen Levels

The breeding season of S. macroura extends from June to February, and individual males (both wild- caught and laboratory-reared) are capable of breeding over extended periods during the breeding season, and for up to three seasons, in the laboratory. Gross and histological changes in the reproductive organs and endocrine changes in relation to reproductive activity have been investigated. Males do not appear to reach sexual maturity until the season following that in which they were born, although spermatorrhoea may commence in the season of birth. Testis and epididymis weight of these males, which commence spermatorrhoea late in the season, approximates that of sexually mature males early in the season but androgen levels and the weight of the accessory glands are low in all males except during the early months of the season. The age at which spermatorrhoea commences ranges from 141 to 350 days. The minimum scrota1 width at which it commences is 7.9 mm and the minimum body weight, 14.0 g. The onset of spermatorrhoea is not a function of age or season and in S. macroura should be used with caution as an indicator of impending sexual maturity. Maximum corticosteroid- binding capacity (MCBC) generally exceeded corticosteroid concentration and no androgen-related fall in MCBC was evident.

scholarly journals ABUNDANCIA Y MADUREZ SEXUAL DE ANADARA SIMILIS EN EL MANGLAR DE LUISICO, BAHÍA MÁLAGA, PACÍFICO COLOMBIANO

2016 ◽  
Vol 42 (2) ◽  
Author(s):  
Alex E. Manjarrés Villamil ◽  
Carlos H. Lucero Rincón ◽  
William O. Gualteros ◽  
Jaime R. Cantera Kintz ◽  
Diego L. Gil Agudelo
Keyword(s):  
Sexual Maturity ◽  
Pacific Coast ◽  
Management Strategies ◽  
First Record ◽  
Reproductive Activity ◽  
Microscopic Level ◽  
Reproductive Tissue ◽  
Histological Techniques ◽  
Mean Size ◽  
The Mean

The abundance and sexual maturity of piangua Anadara similis in La Plata Archipelago, Bahía Málaga, Pacific coast of Colombia, was analyzed between September 2009 and August 2010. Sexual maturity of these organisms was studied at macroscopic level using fresh samples and at microscopic level using standard histological techniques. The mean density was estimated in 0.130 ± 0.098 ind/m2 and the mean size was 42.30 ± 5.00 mm. Months with the presence of the highest densities of piangua were May (0.295 ind/m2) and August (0.195 ind/m2). The mean sexual maturity size was estimated in 41.8 ± 4.5 mm, while the size at which at least 50% of the population of A. similis have had its first spawn was estimated in 41 mm. Reproductive activity of the species was present year-round with higher peaks in March (83.33%) and April (75.00%). 4.30% of organisms analyzed showed signs of hermaphroditism, being this the first record of this kind for the species. Higher density, larger mean size, higher meat yield in females as well as the presence of more female reproductive tissue, suggest a process of sexual reversion in the species, which have to be further studied. Low capture and sexual maturity sizes, as well as the low density of organisms found during the present work, might be the product of high fishery pressure, habitat modifications, and pollution processes in the area, factors that have to be studied in detail in order to implement management strategies for the species.

scholarly journals Size, sex and maturity of the squid Lolliguncula diomedeae (Cephalopoda: Loliginidae) in the Gulf of Tehuantepec, México.

2015 ◽  
Vol 7 (1) ◽  
pp. 79-87
Author(s):  
María del Carmen Alejo-Plata ◽  
José Luis Gómez-Márquez ◽  
Jorge Eduardo Herrera-Galindo
Keyword(s):  
Sexual Maturity ◽  
Gonadosomatic Index ◽  
Reproductive Activity ◽  
Allometric Growth ◽  
Relationship Type ◽  
Length Relationship ◽  
Gulf Of Tehuantepec ◽  
Males And Females ◽  
First Maturity ◽  
Size At First Maturity

There is practically no information on the biology of Lolliguncula (Loliolopsis) diomedeae. We analyzed specimens caught in four shrimp fishing trips in the Gulf of Tehuantepec in 1999-2001, 2004 and 2006.Sexual maturity and gonadosomatic index (GSI) were used as indicators of reproductive activity. A total of 1 200 individuals were captured, 89% female. Females ranged from 35 to 97mm in mantle length (LDM),with a mode at 80mm and weights 2 to 30,9g; males 20,7 to 65mm LDM with a mode at 35-40mm and weights from 0,4 to 12g. Differences in the LDM and the PT between males and females were significant (KS, p<0,05). The sex ratio was 8:1 H:M (p <0,05). The weight-length relationship type is potential for both sexes, with a negative allometric growth.83% of mature females had high IGS values, in contrast to less than 20% of mature males. The size at first maturity (L50) indicates that males (42,7mm LDM) mature when shorter than females (74,5mm LDM). Maturity, IGS and oceanographic features of the Gulf of Tehuantepec indicate that L. diomedeae spawn there.

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