Seahorse

This page is about a genus that contains extinct and extant species; species marked with † are extinct.

## Statistics

### Diet

Planktivorous

*Hippocampus*, or a seahorses, is a genus of small fish that has lived worldwide since the Early Miocene or Late Oligocene.

## Classification

Anatomical evidence supported by molecular, physical and genetic evidence suggests that *Hippocampus* are extremely-modified pipefish. However, the seahorse fossil record is sparse. The most well-studied specimens are of the extant species *H. guttulatus*/*ramulosus*, known from the Marecchia River Formation, Rimini Province, Italy (Lower Pliocene-aged, 3 million years old). The earliest *Hippocampus* are *Hippocampus sarmaticus* and *Hippocampus slovenicus* of the coprolitic horizon, Tunjice Hills, Middle-Miocene (13 million years old) aged Lagerstätten in Slovenia. However, molecular evidence suggests Hippocampus diverged in the Late Oligocene. Thus, it is speculated the genus arose in response to large expanses of shallows being created by tectonic events. This would have allowed for seagrass to expand, in turn, allowing seahorses to camouflage in their upright posture. These tectonic events happened in the western Pacific, with molecular data suggesting two separate invasions in the Atlantic, This would definatively place the origins of Hippocampus in the Pacific. In 2016, a Nature study found the seahorse genome is the most rapidly-evolved genome known.

## Species

* *H. abdominalis* (big-belly seahorse)
* *H. algiricus* (West African seahorse)
* *H. angustus* (narrow-bellied seahorse)
* *H. barbouri* (Barbour's seahorse)
* *H. bargibanti* (pygmy seahorse)
* *H. breviceps* (short-headed seahorse)
* *H. camelopardalis* (giraffe seahorse)
* *H. capensis* (Knysna seahorse)
* *H. casscsio* (Beibu Bay seahorse)
* *H. colemani* (Coleman's pygmy seahorse)
* *H. comes* (tiger-tail seahorse)
* *H. coronatus* (crowned seahorse)
* *H. dahli* (lowcrown seahorse)
* *H. debelius* (softcoral seahorse)
* *H. denise* (Denise's pygmy seahorse)
* *H. erectus* (lined seahorse)
* *H. fisheri* (Fisher's seahorse)
* *H. guttulatus* (long-snouted seahorse)
* *H. haema* (Korean seahorse)
* *H. hippocampus* (short-snouted seahorse)
* *H. histrix* (spiny seahorse)
* *H. ingens* (Pacific seahorse)
* *H. japapigu* (Japanese pygmy seahorse)
* *H. jayakari* (Jayakar's seahorse)
* *H. jugumus* (collared seahorse)
* *H. kelloggi* (great seahorse)
* *H. kuda* (spotted seahorse)
* *H. minotaur* (bullneck seahorse)
* *H. mohnikei* (Japanese seahorse)
* *H. nalu* (South African/Sodwana pygmy seahorse)
* *H. paradoxus* (paradoxical seahorse)
* *H. patagonicus* (Patagonian seahorse)
* *H. planifrons* (flatface/false-eye seahorse)
* *H. pontohi* (Pontoh's pygmy seahorse)
* *H. pusillus* (pygmy thorny seahorse)
* *H. reidi* (longsnout seahorse)
* *H. satomiae* (Satomi's pygmy seahorse)
* *H. sindonis* (Sindo's seahorse)
* *H. spinosissimus* (hedgehog seahorse)
* *H. subelongatus* (West Australian seahorse)
* *H. trimaculatus* (longnose seahorse)
* *H. tyro* (Tyro seahorse)
* *H. waleananus* (Walea soft coral pygmy seahorse)
* *H. whitei* (White's seahorse)
* *H. zebra* (zebra seahorse)
* *H. zosterae* (dwarf seahorse)
* †*H. slovenicus*
* †*H. sarmaticus*

## Synonyms

* *Acentronura*
* *Farlapiscis/Farlapiscus*
* *Hippohystrix*
* *Jamsus*
* *Macleayina*
* *Phyllopteryx*

## References

* https://en.wikipedia.org/wiki/Hippocampus\_slovenicus
* https://en.wikipedia.org/wiki/Hippocampus\_sarmaticus
* https://en.wikipedia.org/wiki/Seahorse
* https://paleobiodb.org/classic/basicTaxonInfo?taxon\_no=35862