The big-belly seahorse (''Hippocampus abdominalis'') or pot-bellied seahorse is one of the largest

seahorse A seahorse (also written ''sea-horse'' and ''sea horse'') is any of 46 species of small marine fish in the genus ''Hippocampus''. "Hippocampus" comes from the Ancient Greek (), itself from () meaning "horse" and () meaning "sea monster" or " ...

species in the world, with a length of up to , and is the largest in Australia. Seahorses are members of the family

Syngnathidae The Syngnathidae is a family of fish which includes seahorses, pipefishes, and seadragons (''Phycodurus'' and ''Phyllopteryx''). The name is derived from grc, σύν (), meaning "together", and (), meaning "jaw". The fused jaw is one of the tra ...

, and are

teleost Teleostei (; Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts ), is, by far, the largest infraclass in the class Actinopterygii, the ray-finned fishes, containing 96% of all extant species of fish. Tel ...

fishes. They are found in southeast

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

and

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

, and are listed on Appendix II of

CITES CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...

Habitat

The big-belly seahorse is found among

alga Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mi ...

seagrass Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the orde ...

es, and rocky

reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock out ...

s in shallow water, and attached to

sponges Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through ...

and colonial

hydroids Hydroids are a life stage for most animals of the class Hydrozoa, small predators related to jellyfish. Some hydroids such as the freshwater '' Hydra'' are solitary, with the polyp attached directly to the substrate. When these produce buds ...

in deeper areas. They also attach to

jetty A jetty is a structure that projects from land out into water. A jetty may serve as a breakwater, as a walkway, or both; or, in pairs, as a means of constricting a channel. The term derives from the French word ', "thrown", signifying somet ...

piles and other manmade objects, and can be found in

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

. They usually inhabit waters less than deep, but have been found as deep as .Lourie, S. A., Foster, S. J., Cooper, E. W. T. and Vincent, A. C. J. 2004. ''A Guide to the Identification of Seahorses''.

Project Seahorse Project Seahorse is a marine conservation organization committed to the conservation and sustainable use of coastal marine ecosystems in general, and seahorses in particular. It is based at the Institute for the Oceans and Fisheries (University ...

and

TRAFFIC Traffic comprises pedestrians, vehicles, ridden or herded animals, trains, and other conveyances that use public ways (roads) for travel and transportation. Traffic laws govern and regulate traffic, while rules of the road include traffic ...

. 114 pp. Juveniles are

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...

or attached to drifting

seaweed Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...

Description

The big-belly seahorse has a forward-tilted, a long-snouted head, a distended but narrow pot belly, and a long, coiled tail. It swims using its

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

with a vertical stance; when not swimming, it coils its

prehensile Prehensility is the quality of an appendage or organ (anatomy), organ that has Adaptation (biology), adapted for grasping or holding. The word is derived from the Latin term ''prehendere'', meaning "to grasp". The ability to grasp is likely der ...

tail around any suitable growth, such as

, waiting for

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

ic animals to drift by, when they are sucked up by the small mouth set at the tip of the snout much like a vacuum cleaner. Seahorses are voracious feeders, eating mainly

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s, such as shrimp, and other small animals living among the seaweed, such as

copepod Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor) ...

s and

amphipod Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far descr ...

s. They do not chew, so they can eat to excess because of their small gut tract. Each eye moves separately, making it easier for them to see food and predators. Hippocampus abdominalis 1921 Waite Fishes S Austr FMIB 45602

Hippocampus abdominalis 1921 Waite Fishes S Austr FMIB 45602

Distinguishing males from females is easy: The male has a smooth, soft, pouch-like area at the base of its

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...

where the stomach meets the tail on the front side. Males also have a fin there, but it is less obvious. The female has more of a pointed stomach with a very obvious fin at the base of it.

Reproduction

In the wild, breeding can commence when the seahorses are about one year old, and this can be reduced to about eight months when in captivity. Breeding in big-belly seahorses year-round, with peaks in the warmer months. Courtship initiation involves a series of colour changes and postural displays. Dilating the opening of the brood pouch slightly, the male inflates the pouch to balloon-like proportions with water by swimming forwards, or by pushing his body forwards in a pumping action, then closing the pouch opening. At the same time, he lightens his pouch in colour to white or light yellow. The male also brightens his overall body colouration, typically intensifying the yellow. A male repeatedly approaches his selected female with his head tucked down, and

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal co ...

and

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

s rapidly fluttering. Hippocampus abdominalis by Zureks

If the female is not receptive, she ignores the male, which then looks for another potential mate. If no females are receptive, the male stops displaying and deflates the pouch by dilating the pouch opening and bending forwards, expelling the water inside. If a female is receptive to a courting male, she reciprocates with her own color changes and head tucking, typically intensifying the lighter colours such as yellow and white, highlighting the contrast between these colours and her overall darker blotching and banding patterning. A series of short bursts of swimming together in tandem then ensues, sometimes with tails entwined, or with the female tightly rolling her tail up. This has often been described as 'dancing'. After coming to rest, the male attempts to get the female to swim towards the water surface with him by repeatedly pointing his snout upwards. If the female responds by also pointing her snout upwards, then the final stage of courtship follows. This involves both the male and female swimming directly upwards towards the water surface with both their heads pointing upwards and tails pointing straight down. If they reach the water surface, one or both seahorses can often be seen and heard to snap their heads. To transfer her eggs to the male, the female faces the male, slightly above him. Pressing the base of her abdomen against the male's pouch, she then squirts her eggs through the opening in the front of his dilated pouch. The male seahorse brood 300–700 young at a time, and can have up to four broods in summer. Their colouring is a variable shade of brown, mottled with yellow-brown and with darker splotches. The tail is often circled with yellow bands. In deeper water where the tail is anchored to other colourful forms of life, such as

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...

s and

, they often take on these colours.

Aquaculture

The big-belly seahorse is a popular aquarium species and dried specimens are sold as traditional medicine in Asia. Stocks come from the wild or are aquarium-reared. They are easy to keep in aquariums and feed on small shrimp and

crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

. H. Abdominalis.jpg H. Abdominalis -2.jpg

References

* A. B. Wilson and K. M. Martin-Smith (2007) Genetic monogamy despite social promiscuity in the pot-bellied seahorse (''Hippocampus abdominalis''), Molecular Ecology, 16, 2345–2352. * * Tony Ayling & Geoffrey Cox, ''Collins Guide to the Sea Fishes of New Zealand'', (William Collins Publishers Ltd, Auckland, New Zealand 1982) * Chris M. C. Woods, National Institute of Water and Atmospheric Research, Received 16 July 2002; received in revised form 16 October 2002; accepted 14 November 2002 pp. 538. Effects of varying Artemia enrichment on growth and survival of juvenile seahorses, Hippocampus abdominalis. (Aquaculture 220 (2003)). * Chris M. C. WOODS, New Zealand Journal of Marine and Freshwater Research, 2000, Vol. 34 pp. 475–485. Preliminary observations on breeding and rearing the seahorse Hippocampus abdominalis (Teleostei: Syngnathidae) in captivity. (The Royal Society of New Zealand 2000). * Chris M. C. Woods, New Zealand Journal of Marine and Freshwater Research, 2002, Vol. 36: 655–660. Natural diet of the seahorse Hippocampus abdominalis. The Royal Society of New Zealand 2002 * Chris M. C. Woods, New Zealand Journal of Marine and Freshwater Research, 2005, Vol. 39: 881–888 Reproductive output of male seahorses, Hippocampus abdominalis, from Wellington Harbour, New Zealand: implications for conservation. (The Royal Society of New Zealand 2005). * Chris M. C. Woods, National Institute of Water and Atmospheric Research, Received 17 December 1999; received in revised form 2 May 2000; accepted 9 May 2000. pp 377–388. Improving initial survival in cultured seahorses, Hippocampus abdominalis Leeson, 1827 (Teleostei: Syngnathidae) (Aquaculture 190, 2000). * Chris M. C. Woods & FiammaValentino, National Institute of Water and Atmospheric Research,Wellington, New Zealand. Naples Zoological Station‘A. Dohrn’,Villa Comunale1, Naples, Italy. Frozen mysids as an alternative to live Artemia in culturing seahorses Hippocampus abdominalis (Aquaculture Research, 2003 34, 757-763). * Gay, P. (2002, October 18). About seahorses. Southland Times, The. Retrieved March 12, 2008, from Australia/New Zealand Reference Centre database. * Hutchings, C. (1997, January). Secret life of seahorses. Geographical, 69(1), 31. Retrieved March 12, 2008, from Academic Search Premier database. * Schleichert, E. (2000, May). Seahorses. Ranger Rick, 34(5), 30. Retrieved March 12, 2008, from MAS Ultra – School Edition database. * Steeman, M. (2001, December 5). Plan to export seahorses to Asia. Dominion Post, The. Retrieved March 12, 2008, from Australia/New Zealand Reference Centre database.

External links

* Pot-bellied seahorse discussed on

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9 December 2022

New Zealand Pot Bellied Sea Horse

Care sheet for Hippocampus Abdominalis in Aquariums

Seahorse.com

Hippocampus_Abdominalis_Video

Playful Hippocampus Abdominalis Video
{{DEFAULTSORT:Big-belly seahorse

big-belly seahorse The big-belly seahorse (''Hippocampus abdominalis'') or pot-bellied seahorse is one of the largest seahorse species in the world, with a length of up to , and is the largest in Australia. Seahorses are members of the family Syngnathidae, and are ...

Marine fish of Southern Australia Marine fish of Tasmania Marine fish of New Zealand Taxa named by René Lesson

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