Tetrosomus gibbosus

Tetrosomus gibbosus, commonly called camel cowfish because of the hump on its dorsal keel, is one of 22 species in the boxfish family, Ostraciidae.[2] It is a ray finned fish. Other common names include helmet cowfish, humpback turretfish and thornbacked boxfish.[3] It is most closely related to Tetrosomus reipublicae, the smallspine turretfish.[4] T. gibbosus is a species of boxfish native to the Indo-West Pacific, but it has been established in the Mediterranean Sea via Lessepsian migration.[5] It is mainly found at depths of 37–110 m (121–361 ft) on slopes or over muddy bottoms, but can sometimes be seen near shallow seagrass beds.[6] Like other boxfish species, its flesh is poisonous.[6] It feeds on a wide variety of invertebrates and algae.

Camel cowfish
Conservation status
Least Concern  (IUCN 3.1)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Tetraodontiformes
Family:	Ostraciidae
Genus:	Tetrosomus
Species:	T. gibbosus
Binomial name
Tetrosomus gibbosus (Linnaeus, 1758)

It occasionally makes its way into the aquarium trade, but is difficult to keep.[3]

Description

T. gibbosus is normally around 20 cm (7.9 in) long when it is fully grown, but can reach up to 30 cm (11.8 in) in length.[7] Fish in the genus Tetrosomus are characterized by the presence of a carapace, a hard upper shell formed by thick scale plates.[4] The body is completely encased in this bony shell, except for a few small openings such as the mouth, eyes, and gills.[8] The mouth is small with fleshy lips and conical teeth usually numbering less than 15.[8]

Biology

T. gibbosus has poisonous flesh, organs, and spines, and is known to secret poisonous mucus in defense or when it is disturbed.[7] This poison can be fatal to humans or other marine organisms that come into contact it.[7] T. gibbosus is hermaphroditic; all individuals of this species are born female, but some may change into males as they grow.[7] Juveniles live together in small schools, but individuals become solitary as they mature into adulthood.[7] T. gibbosus is an omnivorous species, and its diet is known to include seaweeds, sponges, molluscs, worms, and crustaceans found on the bottom of its habitat.[7]

Distribution and habitat

T. gibbosus lives in shallow tropical waters or warm seas with muddy bottoms, at depths of 37–110 meters (121–361 feet).[8] It is a coastal species that is frequently found in coral reefs.[9] It cannot swim long distances and therefore does not live in pelagic waters.[5] Its conservation status is not of concern in any area except for the South China Sea, where it is considered an endangered species.[9]

Lessepsian migration

A Lessepsian migration refers to the migration of a marine species from the Red Sea to the Mediterranean Sea, facilitated by the opening of the Suez Canal in 1869. A species is considered Lessepsian when it has completed this migration and established a population. T. gibbosus was first found in the Mediterranean Sea in 1988.[10] Both the Red Sea and the Mediterranean Sea have similar salinity levels and temperature ranges, which allows for an easier transition between of these bodies of water.[11][5] It is thought that Lessepsian species migrated due to changing climates, since the geographic land barrier was removed when the Suez Canal was completed.[10] T. gibbosus is now considered an invasive species in the Mediterranean Sea, as this is not included in its native distribution.[10] It is also considered an established species because it has established a growing population and has been found in multiple locations.[11] It is the first species from the family Ostraciidae to be found in the Mediterranean Sea.[5] Due to its inability to swim long distances, T. gibbosus likely took multiple generations to migrate from the Red Sea to the Mediterranean Sea; this is thought to have happened, in part, from northward currents moving eggs and larvae north towards the Mediterranean Sea.[5]

References

1. Collen, B.; Richman, N.; Beresford, A.; Chenery, A. & Ram, M. (2010). "Tetrosomus gibbosus". IUCN Red List of Threatened Species. 2010.CS1 maint: ref=harv (link)old-form url
2. Matsuura, Keiichi (11 November 2014). "Taxonomy and systematics of tetraodontiform fishes: a review focusing primarily on progress in the period from 1980 to 2014". Ichthyological Research. 62 (1): 72–113. doi:10.1007/s10228-014-0444-5.
3. "Saltwater Aquarium Fish for Marine Aquariums: Helmet Cowfish". www.liveaquaria.com. Retrieved 2019-04-26.
4. Santini, Francesco; Sorenson, Laurie; Marcroft, Tina; Dornburg, Alex; Alfaro, Michael E. (January 2013). "A multilocus molecular phylogeny of boxfishes (Aracanidae, Ostraciidae; Tetraodontiformes)". Molecular Phylogenetics and Evolution. 66 (1): 153–160. doi:10.1016/j.ympev.2012.09.022.
5. Spanier, E.; Goren, M. (May 1988). "An Indo-Pacific trunkfish Tetrosomus gibbosus (Linnaeus): first record of the family Ostracionidae in the Mediterranean". Journal of Fish Biology. 32 (5): 797–798. doi:10.1111/j.1095-8649.1988.tb05420.x.
6. Froese, Rainer and Pauly, Daniel, eds. (2015). "Tetrosomus gibbosus" in FishBase. April 2015 version.
7. Ketabi, Ramin; Jamili, Shahla. "Tetrosomus gibbosus (Linnaeus, 1758)". aquaticcommons.org.
8. Matsuura, Keiichi (11 November 2014). "Taxonomy and systematics of tetraodontiform fishes: a review focusing primarily on progress in the period from 1980 to 2014". Ichthyological Research. 62 (1): 72–113. doi:10.1007/s10228-014-0444-5.
9. Arai, Takaomi (12 September 2014). "Diversity and conservation of coral reef fishes in the Malaysian South China Sea". Reviews in Fish Biology and Fisheries. 25 (1): 85–101. doi:10.1007/s11160-014-9371-9.
10. Ben Rais Lasram, Frida; Mouillot, David (27 May 2008). "Increasing southern invasion enhances congruence between endemic and exotic Mediterranean fish fauna". Biological Invasions. 11 (3): 697–711. doi:10.1007/s10530-008-9284-4.
11. Mavruk, Sinan; Avsar, Dursun (14 August 2007). "Non-native fishes in the Mediterranean from the Red Sea, by way of the Suez Canal". Reviews in Fish Biology and Fisheries. 18 (3): 251–262. doi:10.1007/s11160-007-9073-7.