![]() ![]() ![]() When natural reproduction fails, assisted techniques can be employed to overcome barriers. Reproduction of animals in human care sometimes requires more than simple cohabitation of females and males as the physiological and behavioral processes involved can be complex ( Ottinger and Mench, 1989). With further development, artificial insemination represents a powerful tool that could be used for maintaining genetic diversity for animals housed in aquaria and conservation-based breeding programs for elasmobranchs. This study successfully employed artificial insemination to circumvent barriers to natural reproduction in Zebra Sharks. All females produced at least one hatched parthenote. ![]() For the two females housed with the male, no sexual offspring resulted. After the second insemination (September 24 th, 2013), 62 yolked eggs resulted in two sexually produced offspring, 18 and 33 days after insemination, and three parthenogenetic offspring > 213 days post-insemination. After the first insemination (December 15 th, 2011), 143 yolked eggs resulted in no sexually produced offspring and four genetically-confirmed, parthenogenetic offspring. ![]() Hatching success for eggs laid by all three females was monitored to compare natural and artificial insemination modes. To determine if assisted techniques could be used to rescue sexual reproduction, artificial insemination was performed in a singleton female twice over a three-year period using freshly collected semen. Among a population of three female and one male Zebra Sharks ( Stegostoma tigrinum), production of young failed despite constant male presence with two of the females. Maintaining self-sustaining populations of zoo and aquarium collections can be challenged when natural reproduction fails within mixed-sex populations however, reproductive success can sometimes be restored with the application of reproductive technologies. 4Delaware Biotechnology Institute, Center for Bioinformatics & Computational Biology, University of Delaware, Newark, DE, United States.3Wildlife Genetics, Department of Comparative Medicine, Loyola University Medical School, Maywood, IL, United States.2Research and Conservation, Georgia Aquarium, Atlanta, GA, United States.1Aquarium of the Pacific, Long Beach, CA, United States.43278).Lance Adams 1*, Kady Lyons 2, Elizabeth Larkin 1, Nicole Leier 1, Janet Monday 1, Chris Plante 1, Jean Dubach 3 and Jennifer Wyffels 4 Reported from freshwater in the Philippines but needs to be confirmed (Ref. Caught in drift net intended for sharks (Ref. Utilized fresh and dried-salted for human consumption and also for fishmeal livers processed for vitamins fins dried for the oriental sharkfin trade offal utilized for fishmeal (Ref. Slow-swimming and able to squirm into narrow cracks, crevices and channel in reefs while searching for food (Ref. Also known to eat crustaceans (crabs and shrimps) and sea snakes (Ref. Probably nocturnal, feeds mainly on mollusks, but also small bony fishes (Ref. Rather sluggish at least during the day (Ref. Recorded to have entered freshwater (Ref. 125658).Ī tropical inshore shark found on sand, rubble, or coral bottoms of the continental and insular shelves (Ref. Two color morphs, with a three-stage ontogenetic color and pattern change: the Zebra morph with juveniles with dark brown background and cream colored bands (zebra-like), transitionals light brown with dark bands, broken up by dots and adults beige to yellow with spotted pattern (can be leopard-like) the sandy color morph: transitionals light beige background with swirly pattern of narrow, darker brown bands with tiny spots breaking up the pattern and with adults uniformly sandy beige with tiny dark brown freckles (Ref. 66-88% of pectoral fin vertebrae total 207-262, monospondylous precaudal 43-49, diplospondylous precaudal 38-50, diplospondylous caudal 120-175, precaudal vertebrae 81-101 tooth rows on upper jaw 13-30, on lower jaw 22-30, and series count, upper jaw: 7-27, lower 8-16 ring-type intestine with 18-20 valvular turns. This species is distinguished by the following characters: a long caudal fin (49.9-54.2% TL), five dorsolateral ridges along the body, visible even in hatchlings spiracles bean-shaped, large (length 0.4-1.7% TL) eyes small (length 0.9-2.1% TL) barbels two and short (0.6-2.8% TL) gill slits five, with fourth and fifth partly fused so only four noticeable from a distance pectoral fins large (anterior margin length 10.4-19.1% TL), are broad and rounded first dorsal fin originates far posteriorly above the pelvic fins pectoral-fin rays of semi-plesodic structure, reaching ca. ![]()
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