Chain catshark
Chain catshark | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Chondrichthyes |
Subclass: | Elasmobranchii |
Subdivision: | Selachimorpha |
Order: | Carcharhiniformes |
Family: | Scyliorhinidae |
Genus: | Scyliorhinus |
Species: | S. retifer
|
Binomial name | |
Scyliorhinus retifer (Garman, 1881)
| |
Range of the chain catshark | |
Synonyms | |
Scyllium retiferum Garman, 1881 |
The chain catshark or chain dogfish (Scyliorhinus retifer) is a small, reticulated
Distribution
The chain catshark is found in the Northwest Atlantic,
Temperature is thought to limit the shark's distribution in northern areas, particularly during the winter. Although bands of warm water at the edge of the shelf have been observed, the temperature varies seasonally, thus limiting this non-migratory species.[2] In general, the chain catshark is found in waters with a temperature between 8.5 °C (47 °F)[5] and 14 °C (57 °F).[6]
-
Jaws
-
Upper teeth
-
Lower teeth
Habitat and behavior
The catshark spends the daytime resting at the bottom, usually in contact with certain structures. It has been observed with large burrowing cerianthid
Reproduction
Size and sexual maturity
The maximum length of this shark is 59 centimeters (1.94 ft).[6]
In the female chain catshark, follicle development has been correlated to nidamental gland size, thus, they are considered mature when they have a fully developed nidamental gland or shell gland.[4] This is marked by the glands growth to 1.8 cm (0.7 in) or more in width. Sexual maturity in the female is seen at 52 centimeters (1.71 ft) in length under normal conditions. There has been evidence however that some northern populations of the shark may mature at a smaller size, at 41 centimeters (1.35 ft). In the male catshark, testis development is correlated to clasper size, thus maturity is marked when it develops hardened claspers that are 3 cm (1.2 in) or more in length.[4][8] Males reach maturity at a length between 37 and 50 centimeters (1.21–1.64 ft).[6]
Mating
Observed mating between the species suggests biting plays an element and that mating occurs repeatedly. Behavioral observations include the male biting the female until it can get a firm grasp and subsequently wraps its body around the female for copulation.[4] After copulation, the male releases his bite and both separate.
Egg-laying
The chain catshark prefers vertical structures for egg deposition and always deposits eggs in pairs. The interval between pairs of eggs ranges from a few minutes to 8 days.[4] Development rates average 1 mm diameter per 7.7 days although temperature has also been seen to affect follicle development.[4]
Sperm storage and egg cases
The female chain catshark is able to store sperm and lay eggs several days after initial copulation. The shark has been known to store sperm up to 843 days although, there are some circumstances of poor egg development in eggs laid later. It is suggested that this could be due to a number of factors including, senescence, low sperm viability, or water quality factors.[4]
Egg cases found in the oviduct are soft, pale yellow and translucent. They also feature two coiled tendrils, a key adaptation which allows snagging on rocks or man made structures, providing grounding and safety. When deposited, they become hardened and become dark amber with white bands.[9]
Embryos
Embryos take 8–12 months to develop due to temperature variations in the environment. The catshark lays eggs in their blastodisc form. The following exhibits a typical developmental timeline (measurements are embryo length):[4]
- 10 mm (0.4 in) – it has well-defined gill arches and has a thin ventral finfold
- 21 mm (0.8 in) – dorsal and pelvic fin buds appear
- 33 mm (1.3 in) – embryo has protruding eyes and well-developed gill filaments
- 43 mm (1.7 in) – it has lost its translucency and develops slits in the egg case, allowing fluid exchange from surrounding seawater and the interior
- 58 mm (2.3 in) – the finfold starts to decay
- 66 mm (2.6 in) – the finfold and gill filaments are reduced or absent
- 74 mm (2.9 in) – external appearance is complete but yolk sac is still being absorbed
- 100–110 mm (3.9–4.3 in) – hatching
Fluorescence
The chain catshark is one of four
Relationship with humans
The chain catshark is not currently fished for human consumption.[1][13]
The chain catshark has been described as "gorgeous",[14] and this, combined with its small size, makes it a popular cold-water aquarium fish.[7][13] It is frequently displayed and bred at public aquariums.[4][7] Research in shark behavior, including reproduction, has been done in chain catsharks kept in public aquariums or laboratories.[4][6]
References
- ^ . Retrieved 9 November 2022.
- ^ JSTOR 1446270.
- ^ Chain Catsharks, Scyliorhinus retifer Archived 2016-11-21 at the Wayback Machine. marinebio.org
- ^ JSTOR 1445396.
- ^ a b Froese, Rainer; Pauly, Daniel (eds.) (2017). "Scyliorhinus retifer" in FishBase. September 2017 version.
- ^ a b c d "Chain Catshark". ReefQuest Centre for Shark Research. Retrieved 6 September 2017.
- ^ a b c "A Deep-Sea Shark for the Home Aquarium". Absolutely Fish. 6 January 2016. Retrieved 6 September 2017.
- JSTOR 1446564.
- ^ Chain Dogfish Archived 2011-02-10 at the Wayback Machine. flmnh.ufl.edu
- ^ PMID 27109385.
- ^ "EXCLUSIVE: How "Glowing" Sharks See Each Other". video.nationalgeographic.com. Archived from the original on April 27, 2016. Retrieved 2016-05-11.
- PMC 6831821.
- ^ a b "Chain Dogfish". Florida Museum. Retrieved 6 September 2017.
- ^ Michael, Scott W. (March 2004), "Sharks at Home", Aquarium Fish Magazine, pp. 20–29