Reproductive cycle, nutrition and growth of captive blue spotted stingray,Dasyatis kuhlii(Dasyatidae)

Abstract

At Burgers' Ocean 7 male and 3 female blue spotted stingrays, Dasyatis kuhlii were born over a period of 4.5 years. This paper describes the experiences of the captive breeding results of this species. The first two young died within 2 days of birth. One of them had an internal yolk sac, which may feed the young in the first few days. The other eight animals started to feed after 4 to 9 days on a variety of food types. Birth size of the young increased with increasing age of the parents. Mating occurred directly after parturition, so no seasonality could be defined. Gestation length ranged between 138 and 169 days, with a mean of 144.9 + 9.0 days (N ¼ 11). Litter size was one, possibly caused by only one active ovarium. Sexual maturity of the two parent animals is approximately 3.5 years. The average feeding rations for the adults ranged between 10.1% BW week 21 (131 kcal kg BW 21 week 21 ) and 11.3% BW week 21 (172 kcal kg BW 21 week 21 ), with a feeding frequency of 4 times per week. The relationship between body weight (BW) and wingspan (WS) is given as BW ¼ 3.6 Â 10 25 * WS 2.940 (R 2 ¼ 0.9645; N ¼ 45).

Reproductive biology of the pelagic stingray, Pteroplatytrygon violacea (Bonaparte, 1832), in the equatorial and south-western Atlantic Ocean

“…These results also suggest that ovarian development probably speeds up in the later stages of pregnancy, and that females are probably able to ovulate soon after parturition. This condition has been observed in other studies of the pelagic stingray and in other dasyatids (Capapé 1993;Hemida et al 2003;Chapman et al 2003;Janse and Schrama 2010).…”

Reproductive parameters of the southern stingray Dasyatis Americana in southern gulf of Mexico

“…Grubbs et al (2006) (Snelson et al, 1989;Johnson & Snelson, 1996;Ebert & Cowley, 2008). The biannual reproductive cycle for wild specimens has been suggested for two species only, D. marianae and D. guttata (Yokota & Lessa, 2007), and for captive specimens, it has been determined for three species, D. americana, D. kuhlii and Pteroplatytrygon violacea (Henningsen, 2000;Mollet et al, 2002;Janse & Schrama, 2009). An uncommon triannual cycle of reproduction among elasmobranchs has been suggested for D. marmorata in wild specimens (Capapé & Zaouali, 1995), however, the authors do not explore the possibility of an asynchronous reproductive cycle for this species, in which case, a different methodology must be used, such as the proposed by Braccinni et al (2006).…”

Contraception within an elasmobranch captive breeding programme: a case report on the eagle ray Aetobatus ocellatus using gonadotrophin‐releasing hormone (GnRH) agonist deslorelin (Suprelorin)

“…After each parturition in A. ocellatus , chasing behaviour within the males was observed, resulting in bite marks on the trailing edge of the pectoral fins. Bite marks are known to be a common sign of mating behaviour in rays (Henningsen et al ., ; Janse & Schrama, ; Kajiura et al ., ; Nordell, ). After the last parturition of this female this behaviour was seen, resulting in fin scars on the female suggesting mating behaviour.…”