Annual reproductive activity of Caiman crocodilus fuscus in captivity

Abstract

We describe the gonadal and abdominal fat storage cycles for a population of Caiman crocodilus fuscus kept in captivity at a breeding farm. The reproductive cycles of males and females are clearly seasonal. Vitellogenic follicles were observed in females year-round; however, the follicular growth that produces the preovulatory follicles for the breeding season occurs in November-May (most of the dry season to the beginning of the rainy season). These months correspond with the presence of physiologically reproductive males. Oviposition takes place during the wet season (April-August) and the births occur at the end of this season (September-November). Fat storage was not related to reproductive activity, and did not vary by month or between sexes. Although environmental and hormonal conditions have been improved for these captive animals, they maintain a strongly seasonal reproductive cycle, historically fixed to oviposit in the most favorable period for nest construction and hatching during the rainy season.

Histological Study of the Male Internal Genital Tract of Dwarf Caiman (Paleosuchus palpebrosus Cuvier, 1807)

“…Similar histological characteristics of the epididymis (Figure A, D) were reported in other alligators [7,[14][15][16][17] . Similarly to Paleosuchus palpebrosus, in Crocodylus porosus the epithelium is formed by non-ciliated and ciliated cells structured into a simple columnar lining of the ductus efferent through to the high pseudostratified columnar epithelium of the epididymis and ductus deferens [5] .…”

Sources of intraspecific variation in the isotopic niche of a semi-aquatic predator in a human-modified landscape

“…We also classified caimans into four size classes due to sexual dimorphism in size ( Ayarzaguena, 1983 ; Thorbjarnarson, 1993 ): hatchlings (Class I = SVL < 20 cm), juveniles (Class II = 20 ≥ SVL < 60 cm), sub-adults males/adult females (Class III = 60 ≥ SVL < 90 cm), and adult males (Class IV = SVL ≥ 90 cm). Males and females achieve sexual maturity at different sizes, with Class III comprehending reproductively active females (SVL > 60 cm), sub-adult males, and small adult males (maturity from SVL > 70 cm), while Class IV consists of mature males ( Guerrero et al, 2003 ; Souza et al, 2010 ; Thorbjarnarson, 1994 ). We conducted this study under permit SISBIO #13324-6, issued by Instituto Chico Mendes de Conservação da Biodiversidade—ICMBio, and CEUA-UnB #33786/2016, issued by Comissão de Ética no Uso de Animais da Universidade de Brasília.…”

Behavior in a captive family group of Siamese Crocodiles (Crocodylus siamensis) at the Madras Crocodile Bank Trust near Chennai, India

“…Based on previous studies of other species and observations of these Siamese Crocodiles by the author and staff at the MCBT, we examined the following hypotheses: H 1 : Attempts by the male to initiate courtship should peak 2-3 months before oviposition by the female (e.g., Guerrero et al 2003); H 2 : Attempts by parents to catch young will increase in frequency when hatchlings reach a critical size (or display or cease to display a specific behavior such as vocalization) related to terminating parental care (e.g., Hunt 1977; Hunt and Watanabe 1982); H 3 : Assertive displays by parents (territorial behaviors such as "head slapping"; Lang 1987) will increase in frequency as hatchlings reach critical size; H 4 : Juveniles will become more successful at foraging in water and land (Whitaker 2007); and H 5 : Vocalizations by juveniles will reach maximum frequencies as parents increasingly attempt to catch juveniles.…”