Psychrolutidae

Psychrolutidae
Blob sculpin (Psychrolutes phrictus) in its natural state
Psychrolutes phrictus removed from the water, its body swollen by the low pressure
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Scorpaeniformes
Superfamily: Cottoidea
Family: Psychrolutidae
T. N. Gill, 1861
Genera[1]

see text

The fish family Psychrolutidae (commonly known as blobfishes,[2] south america river teacher,[2] flathead sculpins,[2] or tadpole sculpins[2]) contains over 35 recognized species in 8 genera.[3] This family consists of bottom-dwelling marine sculpins shaped like tadpoles, with large heads and bodies that taper back into small, flat tails. The skin is loosely attached and movable, and the layer underneath it is gelatinous. The eyes are placed high on the head, focused forward closer to the tip of the snout. Members of the family generally have large, leaf-like pectoral fins and lack scales, although some species are covered with soft spines. This is important to the species as the depths in which they live are highly pressurized and they are ambush/opportunistic/foraging predators that do not expend energy unless they are forced to.

The blobfish has a short, broad tongue and conical teeth that are slightly recurved and are arranged in bands in irregular rows along the premaxillaries; canines are completely absent. Teeth are nonexistent on the palatines and vomer; which make up the hard palate. The blobfish also has a set of specialized pharyngeal teeth that are well developed and paired evenly along the upper and lower portions of the pharyngeal arch. These specialized teeth may aid in the breakdown of food due to the very strategic dependency on whatever food falls from above.[4]

They are found in the Atlantic and Pacific Ocean. Psychrolutes phrictus have been reported near the Mexican Pacific coast, which extends the southern range by 1,733 km.[5] Myoxocephalus thompsonii, deepwater sculpin, have even been reported in Lake Ontario which were once thought to be extirpated.[6] Psychrolutidae species tend to habituate the northern most region of the Pacific ocean due to lower temperatures, and Indian Oceans. They are found in depths ranging from 300–1,700 meters. The adults live on the sea floor, between 100 and 2,800 m (330 and 9,190 ft) deep,[7][8] The intense biological pressure to conserve energy within deep sea fish seems to be true across many species; most of them are long lived, have a slow rate of reproduction, growth, and aging. Furthermore, studies have shown that the Psychrolutidae species displays a wide range of reproductive patterns, which include group synchronous maturation and extended batch spawning, which highlights their adjustment to deep sea habitats. In this case the blobfish can live to be roughly 130 years old. Categorized as the predator of the deep sea they have no real predatory issues; a big help to aid in their energy saving. Their diet also helps in their energy saving abilities. They feed on small crustaceans, sea pens, sea worms, and any other small organisms that swim right in front of them. Their name is derived from the Greek psychrolouteo, meaning "to have a cold bath".[8] They tend to live in colder waters, although some range into warm-temperate seas.[9]

The blob sculpin, Psychrolutes phrictus, exhibits complex nesting behaviors complete with egg guarding.[10] Reproductively the blobfish have been seen gathering in large numbers to lay their pinkish eggs in a single surrounding nesting area. The number of eggs laid within one nest can range from 9,000 to 108,000. Another observation of the parental care of the blobfish is that their eggs resemble being cleaned. It is believed that as the female blobfish hover around the nests they also clean them and remove any sand or dirt.

  1. ^ Froese, Rainer; Pauly, Daniel (eds.). "Family Psychrolutidae". FishBase. December 2012 version.
  2. ^ a b c d "Psychrolutidae – Names". Atlas of Living Australia. Retrieved 2019-03-28.
  3. ^ Bray, D.J. (2019). "Blobfish Psychrolutidae". Fishes of Australia. Retrieved 18 November 2022.
  4. ^ McCulloch, Allan. 1914. Report on some Fishes obtained by the F.I.S. “Endeavour” on the coasts of Queensland, New South Wales, Victoria, Tasmania, South and south-western Australia. Australian Museum, Sydney. Vol 5. Issue 4. Pages 187-194, 215-216, Plate LV.
  5. ^ Aguirre-Villaseñor, Hugo; Cruz-Acevedo, Edgar; Salas-Singh, Carolina (2016-09-01). "New eastern Pacific Ocean record of the rare deep-water fish, Psychrolutes phrictus (Scorpaeniformes: Psychrolutidae)". Revista Mexicana de Biodiversidad. 87 (3): 1141–1145. doi:10.1016/j.rmb.2016.06.013. ISSN 1870-3453.
  6. ^ Welsh, Amy B.; Scribner, Kim T.; Stott, Wendylee; Walsh, Maureen (2017). "A population on the rise: The origin of deepwater sculpin in Lake Ontario". Journal of Great Lakes Research. 43 (5): 863–870. Bibcode:2017JGLR...43..863W. doi:10.1016/j.jglr.2017.04.009.
  7. ^ Eschmeyer, William M. (1998). Paxton, J.R.; Eschmeyer, W.N. (eds.). Encyclopedia of Fishes. San Diego: Academic Press. p. 179. ISBN 0-12-547665-5.
  8. ^ a b "Family Psychrolutidae - Fatheads". FishBase. 26 Aug 2010. Retrieved 13 September 2012.
  9. ^ Richards, William J. (2005). Early Stages of Atlantic Fishes: An Identification Guide for the Western Central North Atlantic. CRC Press. p. 1191. ISBN 978-0-203-50021-7.
  10. ^ Drazen, Jeffrey C.; Goffredi, Shana K.; Schlining, Brian; Stakes, Debra S. (2003). "Aggregations of Egg-Brooding Deep-Sea Fish and Cephalopods on the Gorda Escarpment: a Reproductive Hot Spot". Biological Bulletin. 205 (1): 1–7. doi:10.2307/1543439. JSTOR 1543439. PMID 12917216. S2CID 27989243.