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

2006 ◽  
Vol 27 (1) ◽  
pp. 25-36 ◽  
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.

VARIATION AMONG INDIVIDUALS AND THE EFFECT OF TEMPERATURE ON FOOD CONSUMPTION AND REPRODUCTION IN THE COCKROACH, PERIPLANETA AMERICANA (ORTHOPTERA: BLATTIDAE)

1984 ◽  
Vol 116 (6) ◽  
pp. 785-793 ◽  
Author(s):  
C. David Rollo ◽  
Marvin W. Gunderman
Keyword(s):  
Food Consumption ◽  
Reproductive Cycle ◽  
Periplaneta Americana ◽  
Effect Of Temperature ◽  
Adult Males ◽  
Feeding Rates ◽  
Males And Females ◽  
Reproductive Cycles ◽  
Individual Adult

AbstractLong term daily feeding in individual adult males and females of Periplaneta americana (L.) was quantified using a standardized diet. There was considerable variation among days, probably related to digestive processes with a period greater than 1 day. Female feeding was correlated with the reproductive cycle, most feeding occurring during the first few days after depositing an oötheca. Females differed with respect to the length of their reproductive cycles, and the amount of food that was accumulated prior to producing an oötheca. Females with high feeding rates produced oöthecae at a faster rate, but they were less efficient at converting food into oöthecal biomass than females that ate more slowly. A decrease in temperature from 25 °C to 20 °C more than doubled the length of the reproductive cycle, but the amount of food accumulated during inter-ovipositional intervals and the size of the oöthecae were not affected.

Reproduction in the Indian mouse-tailed bat, Rhinopoma hardwickei hardwickei (Chiroptera, Rhinopomatidae)

1989 ◽  
Vol 1 (3) ◽  
pp. 255 ◽  
Author(s):  
KB Karim ◽  
S Banerjee
Keyword(s):  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Uttar Pradesh ◽  
Gestation Period ◽  
Equal Frequency ◽  
Annual Reproductive Cycle ◽  
Males And Females

At and near Agra, in Uttar Pradesh, India, R. h. hardwickei had a strictly defined annual reproductive cycle. Although many females were inseminated during late February to mid April, ovulation was not recorded until 11 March. Progressively more females ovulated and conceived during the following weeks until the end of April and released one ovum from either of the ovaries with nearly equal frequency. A single conceptus was carried in the ipsilateral uterine cornu during each cycle. The gestation period was 95-100 days. Births occurred between the second week of June and the end of July. Lactation lasted at least 20 days. Females attained sexual maturity at an age of 8.5-9.0 months. Males took at least 16-17 months to attain sexual maturity. Females were segregated during lactation; during the rest of the year, males and females lived together.

Reproduction of the water snake Helicops infrataeniatus (Colubridae) in southern Brazil

2005 ◽  
Vol 26 (4) ◽  
pp. 527-533 ◽  
Author(s):  
Luís Felipe Schmidt de Aguiar ◽  
Marcos Di-Bernardo
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Statistical Difference ◽  
Rio Grande ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Water Snake ◽  
Males And Females ◽  
Two Peaks

AbstractThe reproductive cycle, sexual maturity, fecundity, and sexual dimorphism of Helicops infrataeniatus Jan, 1865, were inferred from the analysis of 374 preserved specimens (110 males, 140 females) from the eastern Central Depression of Rio Grande do Sul, Brazil. There was no statistical difference between the SVL of newborn males and females, but mature females attained greater length than mature males. The tail of mature individuals was proportionally longer in males than in females. Males matured at a smaller size than females. The reproductive cycle of this species was longer than what is known for oviparous colubrids from subtropical and temperate zones of Brazil. In the studied population, vitellogenesis occurred from September to February. Oviductal embryos were found from September to May. Births took place in September, January, February and March, and occurred in two peaks. Litter size ranged from 5 to 22 offspring. The differences between the number of vitellogenic follicles and embryos, and between embryos and newborns were not significant, thus practically all follicles were generally converted into embryos and embryos into newborns.

Reproductive biology of the Sword Snake Tomodon dorsatus (Serpentes: Dipsadidae) in South Brazil: comparisons within the tribe Tachymenini

2020 ◽  
Vol 41 (4) ◽  
pp. 445-459
Author(s):  
Luiza Loebens ◽  
Selma Maria Almeida-Santos ◽  
Sonia Zanini Cechin
Keyword(s):  
Reproductive Cycle ◽  
Reproductive Strategies ◽  
Sexual Maturity ◽  
Reproductive Effort ◽  
Caudal Vertebra ◽  
Ductus Deferens ◽  
Histological Changes ◽  
Males And Females ◽  
Autumn And Winter ◽  
South Brazil

Abstract We described the reproductive cycle, size-fecundity relationships, reproductive effort, and sexual maturity of Tomodon dorsatus in South Brazil. We examined 87 individuals (25 males and 62 females) from herpetological collections. The description of the reproductive cycle was based on the morpho-anatomical and histological changes in male testes, ductus deferens, and kidney and in female ovary and oviduct. The age at the onset of sexual maturity was estimated by skeletochronology of the caudal vertebra. The reproduction is seasonal semi-synchronous with most of the individuals showing a reproductive peak in the spring. Males and females have developed sperm storage strategies, increasing the reproductive success. Males store sperm in the ductus deferens during the autumn and winter, while females storage takes place in the utero-vaginal junction furrows during the autumn and early winter. Larger females produce a higher number of larger follicles and eggs. Females invest more in growth before reaching sexual maturity than males. Females reach sexual maturity earlier (4 years old) than males (5 years old) and have larger bodies but lower longevity. Reproductive strategies of Tachymenini specie are highly conserved.

scholarly journals Reproductive biology of Thamnodynastes hypoconia (Serpentes: Dipsadidae) in Brazilian subtemperate wetlands

2016 ◽  
Vol 88 (3 suppl) ◽  
pp. 1699-1709 ◽  
Author(s):  
MARLUCI M. REBELATO ◽  
GLÁUCIA M.F. PONTES ◽  
ALEXANDRO M. TOZETTI
Keyword(s):  
Body Size ◽  
Reproductive Success ◽  
Reproductive Biology ◽  
Reproductive Cycle ◽  
Related Species ◽  
Sexual Maturity ◽  
Late Summer ◽  
Abundant Species ◽  
Early Fall ◽  
Macroscopic Analysis

ABSTRACT This study aimed to describe the reproductive biology of populations of Thamnodynastes hypoconia in subtemperate wetlands based on macroscopic analyses of their gonads. We analyzed 101 specimens from the southernmost regions of Brazil. The males had a greater snout-vent length, but the females reached sexual maturity with a greater body size. The reproductive cycle of the females was seasonal, with secondary vitellogenesis occurring between the winter and spring (May-October). Based on macroscopic analysis of gonads, data suggests that males have a continuous reproductive cycle. Parturition occurs between the late summer and early fall (January-April). The clutch size ranged between 4 and 16 embryos and showed no relationship with the female's body size. The recorded reproductive frequency of T. hypoconia is low (38 %) compared to other phylogenetically related species. Conversely, the studied populations appear to have a high reproductive success because it is an abundant species in the study site.

RELIABLE SEXING OF ADULT CONOPHTHORUS (COLEOPTERA: SCOLYTIDAE) BEETLES

1995 ◽  
Vol 127 (4) ◽  
pp. 605-607 ◽  
Author(s):  
Jorge A. Santiago-Blay ◽  
Traivis L. Young
Keyword(s):  
Reliable Method ◽  
Abdominal Tergite ◽  
Head Width ◽  
Scanning Electron Micrographs ◽  
Adult Males ◽  
Diagnostic Features ◽  
Genital Opening ◽  
Males And Females ◽  
Non Destructive ◽  
Scanning Electron

Conophthorus Hopkins 1915 cone beetles are among the most damaging pests of pine (Pinus spp.) seed production in North America (Hedlin et al. 1980; Cibrián-Tovar et al. 1986). Current work on cone beetle molecular identification and semiochemicals requires a rapid and reliable method for sexing adult beetles. Head microsculpturation (Schwarz 1895; Wood 1982), overall beetle length, head width, and internal genital structures (or parts of them) visible when extruded through the genital opening (Lyons 1956) have been suggested as characters to sex adult Conophthorus. Herdy (1959) pointed out that abdominal tergite morphology could be used to distinguish males from females. The latter seems to be the most reliable, non-destructive way to sex Conophthorus specimens. Published illustrations (Kinzer and Ridgill 1972) have been found difficult to interpret by many researchers. To increase the reliability in sexing adult Conophthorus beetles, we prepared scanning electron micrographs (SEMs) of the terminal abdominal tergites of adult males and females, which we present here, clearly showing the diagnostic features of each sex.

Age, Sex and Season: Factors which Determine the Trap Response of the European Wild Rabbit, Oryctolagus cuniculus

1980 ◽  
Vol 7 (3) ◽  
pp. 421 ◽  
Author(s):  
JC Daly
Keyword(s):  
Individual Differences ◽  
Natural Population ◽  
Breeding Season ◽  
Sexual Maturity ◽  
Oryctolagus Cuniculus ◽  
Adult Population ◽  
Late Summer ◽  
Wild Rabbit ◽  
Males And Females ◽  
Probability Of Capture

Factors determining the trap-response of the rabbit, investigated in a natural population at Urana, N.S.W., included the age and the sex of the rabbit and the season in which it was trapped. Differences were also observed between rabbits living in two adjacent habitats. Mark-recapture data, derived from 52 trips undertaken over 30 months, did not show a uniform probability of capture within the adult population. Adult rabbits were most trappable when they were not breeding (late summer to midwinter); at this time males and females were equally trappable but individual differences were noted. During the breeding season all adults were difficult to trap, males more so than females. Trappability increased with age in young rabbits and declined at sexual maturity. Trap-response was random with respect to the animal's genotype as determined by four polymorphic enzyme loci. Markrecapture- analysis is unlikely to be an accurate means of estimating the parameters of rabbit populations; full enumeration of the population is necessary.

Allometric growth, sexual maturity, and life cycle of Aegla lata (Decapoda, Anomura), a critically endangered species

2019 ◽  
Vol 39 (6) ◽  
pp. 748-757
Author(s):  
Mariane R Chaves ◽  
Ingrid C Marçal ◽  
Roberto M Shimizu ◽  
Sérgio Ls Bueno ◽  
Gustavo M Teixeira
Keyword(s):  
Endangered Species ◽  
Sexual Maturity ◽  
Development Stage ◽  
Critically Endangered ◽  
Adult Males ◽  
Allometric Growth ◽  
Southern Limit ◽  
Critically Endangered Species ◽  
Small Streams ◽  
Males And Females

Abstract Aegla lata Bond-Buckup & Buckup, 1994 is a critically endangered species, extinct in its type-locality. Its currently known geographical distribution is restricted to small streams of the lower Tibagi River Basin (Paraná state, southern Brazil), where it is vulnerable to the environmental degradation that takes place in these watersheds. Scientific knowledge on the species is limited to the original description and a few occurrence records. No information about its biology is available. Aiming to fill this gap, we investigated the relative growth, sexual maturity, sexual dimorphism, and the reproductive and recruitment periods of A. lata. Monthly sampling occurred from May 2014 through June 2015 in the Bule stream in the southern limit of Mata dos Godoy State Park, Londrina, Paraná state, Brazil (23°27ʹ20.86″S, 51°16ʹ32.44″W). The analysis of allometric growth was used to differentiate juveniles and adults. According to the development stage of the chelae, two sequential groups of adult males were recognized (morphotypes I and II). The estimated average cephalothorax length (CL) at the onset of morphometric maturity of males and females are similar, suggesting puberty molt takes place at nearly the same size in both sexes. Males and females are heterochelous, with a clear predominance of the left chela as the most developed of the pair. Both chelae are larger in adult males than in adult females of similar CL. The reproductive period is markedly seasonal, extending from the austral autumn to winter (May to August), as well as those recorded in other species of Aegla from similar latitudes. A single annual recruitment pulse was detected from October 2014 to February 2015.

High-arctic lemmings, Dicrostonyx groenlandicus. II. Demography

1975 ◽  
Vol 53 (6) ◽  
pp. 867-878 ◽  
Author(s):  
W. A. Fuller ◽  
A. M. Martell ◽  
R. F. C. Smith ◽  
S. W. Speller
Keyword(s):  
Significant Variation ◽  
Sexual Maturity ◽  
Late Summer ◽  
High Arctic ◽  
Age Classes ◽  
Devon Island ◽  
Dicrostonyx Groenlandicus ◽  
Early Maturing ◽  
Males And Females ◽  
Old Females

Captures of Dicrostonyx groenlandicus on northeastern Devon Island peaked in 1969 and 1973, were higher than expected in 1971, and were minimal (< 5 per 1000 trap-nights) in 1970 and 1972. Captures declined from July to August in at least five of seven summers and may have declined in a 6th year (1973). No change was detected in 1972. Body size was maximal in 1973 for mature and immature males and females and for all pelage (=age?) classes. Sexual maturity was delayed, at least in males, in 1973. Wintering females conceive under the snow in May and the litter is weaned at the normal time of snowmelt. Two other summer cohorts are produced by surviving old females and early maturing females of the first litters. None of the late summer cohort matures before the onset of winter. No female examined bore more than two summer litters. Mean summer litter size was 5.7 with no significant variation between years. Mean sex ratio was 50.3% male. It is suggested that density-related effects ought to occur in winter, rather than summer, but evidence on this point is equivocal. Arctic adaptations of D. groenlandicus are discussed.

Sexual dimorphism in the Neotropical lizard, Tropidurus torquatus (Squamata, Tropiduridae)

2005 ◽  
Vol 26 (2) ◽  
pp. 127-137 ◽  
Author(s):  
Helga Wiederhecker ◽  
Adriana Pinto ◽  
Guarino Colli
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Sexual Maturity ◽  
Body Shape ◽  
Patch Size ◽  
Adult Males ◽  
Lizard Species ◽  
Central Brazil ◽  
Adult Females ◽  
Males And Females

AbstractWe describe the sexual dimorphism in coloration, body shape, and body size in Tropidurus torquatus, a widely distributed lizard species in central Brazil. Adult males have colored patches varying from yellow to yellow-and-black, and black on the abdomen, ventral aspect of the thighs, and pre-cloacal flap. Adult females lack ventral colored patches. During ontogeny, there is a gradual darkening of the patches, but no modification either in patch size or color is associated with the reproductive cycle. Adult males have wider heads and thinner bodies than females of the same body size. Males and females grow at the same rate prior to sexual maturity, but males take longer to reach sexual maturity, maturing at a larger body size than females.

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