| Denise's pygmy seahorse | |
|---|---|
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| at Raja Ampat | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Syngnathiformes |
| Family: | Syngnathidae |
| Genus: | Hippocampus |
| Species: | H. denise |
| Binomial name | |
| Hippocampus denise | |
Hippocampus denise, also known as Denise's pygmy seahorse [3] or the yellow pygmy seahorse, is a seahorse of the family Syngnathidae native to the western Pacific.
Denise's pygmy seahorse is a small fish which can reach a maximum length of approximately 2.4 cm, which makes it one of the smallest representatives of the seahorses. [4] This pygmy seahorse has a short snout, slender body with a prehensile tail. Its body is either completely smooth or provided with some polyp-like tubercles, in which case these are fewer and less developed than Hippocampus bargibanti . Its coloration ranges from yellow, more or less bright, to orange with often small dark spots and sometimes darker bands on the tail. [5]
This pygmy seahorse has been reported from several locations in the western Pacific, including Indonesia, Vanuatu, Palau, Malaysia, the Solomon Islands and Micronesia. It can be found at depths between 13 and 100 m, generally hiding in fields of gorgonians (e.g., Annella , Muricella and Echinogorgia ). [4] [5]
Denise's pygmy seahorse uses adaptive camouflage, changing its color to match that of the surrounding gorgonians. [4] It feeds on small crustaceans and other zooplankton. [6] An individual will stay on a single coral for the duration of its entire life. The species is ovoviviparous, and it is the male who broods the eggs in its ventral brood pouch. The latter includes villi rich in capillaries that surround each fertilized egg creating a sort of placenta supplying the embryos. When fully grown, pups are expelled from the pocket and become autonomous. [5] Males have been recorded as giving birth to 6-7 pups after 11 days of gestation, and carrying out four sequential pregnancies of the same gestation length. [7]
The species is relatively rare and only few data relating to the population as well as its actual distribution exist. Because of this lack of information and the rarity of the species, Denise's pygmy seahorse is currently classified as Data Deficient by the IUCN. [1] Internationally, it is also listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) this means that it is on the list of species not necessarily threatened with extinction, but in which trade must be controlled in order to avoid utilization incompatible with their survival. [1]
The common name and the specific name honour the diver and underwater photographer Denise Tackett, who died in 2015; she was diving with Sara Lourie, one of the describers of H. denise, when she first encountered this species in the Lembeh Strait in 1999. [8]
A seahorse is any of 46 species of small marine bony fish in the genus Hippocampus. "Hippocampus" comes from the Ancient Greek hippókampos (ἱππόκαμπος), itself from híppos (ἵππος) meaning "horse" and kámpos (κάμπος) meaning "sea monster" or "sea animal". Having a head and neck suggestive of a horse, seahorses also feature segmented bony armour, an upright posture and a curled prehensile tail. Along with the pipefishes and seadragons they form the family Syngnathidae.
The Syngnathidae is a family of fish which includes seahorses, pipefishes, and seadragons. The name is derived from Ancient Greek: σύν, meaning "together", and γνάθος, meaning "jaw". The fused jaw is one of the traits that the entire family have in common.
The pygmy seahorses comprise several species of tiny seahorse in the syngnathid family or Syngnathidae. Family Syngnathidae is part of order Syngnathiformes, which contains fishes with fused jaws that suck food into tubular mouths. They are found in Southeast Asia in the Coral Triangle area. They are some of the smallest seahorse species in the world, typically measuring less than 2 centimetres (0.79 in) in height.
Hippocampus bargibanti, also known as Bargibant's seahorse or the pygmy seahorse, is a seahorse of the family Syngnathidae found in the central Indo-Pacific area.
Barbour's seahorse is a species of fish of the family Syngnathidae.
The knobby seahorse, also known as the short-headed seahorse or short-snouted seahorse, is a species of marine fish of the family Syngnathidae. It inhabits coastal waters in southwestern and southeastern Australia, from Gregory to Bremer Bay, and from Denial Bay to Newcastle.
The tiger tail seahorse is a species of fish in the family Syngnathidae. The species was first described by Theodore Cantor in 1850. It is found in India, Indonesia, Malaysia, the Philippines, Singapore, Thailand and Vietnam. Its natural habitats are subtidal aquatic beds and coral reefs. It is threatened by habitat loss.
Hippocampus coronatus, commonly known as the high-crowned seahorse or crowned seahorse, is a species of fish of the family Syngnathidae. It is endemic to the Pacific coastal waters of Japan, where it lives among Zostera seagrasses. It can grow to lengths of 10.8 centimetres (4.3 in), but is more commonly 6 centimetres (2.4 in). Individuals feed mainly on small crustaceans such as gammarid amphipods and copepods, although this can vary by size, with smaller individuals consuming copepods while larger individuals feed on amphipods and mysids. This species is ovoviviparous, with males brooding eggs in a brood pouch before giving birth to live young. Breeding season occurs from June to November, with females and males reaching sexual maturity at 6.9 centimetres (2.7 in) and 7.3 centimetres (2.9 in) respectively. Male brood size ranges from 12–46. The International trade in this species has been monitored through Appendix II of the CITES licensing system since 2004 and a minimum size of 10 centimetres (3.9 in) applies to traded specimens.
Hippocampus fisheri, commonly known as Fisher's seahorse, or the Hawaiian seahorse, is a species of fish of the family Syngnathidae. It is known from the Hawaiian Islands, although previous misidentifications indicated species occurrences in Australia and New Caledonia. Habitat preferences are unknown, but it has been found far away from shore and at depths greater than 100 metres (330 ft). Feeding habits are also unknown, but individuals are expected to feed on small crustaceans similar to other seahorses. Hippocampus fisheri is one out of the three species of Hippocampus genus found in the Hawaiian islands. They are also expected to be ovoviviparous, with males carrying eggs in a brood pouch before giving birth to live young. Individuals can grow to lengths of 8 centimetres (3.1 in). The specific name and the common name honour "Walter V. Fisher” of Stanford University. There was a Walter Kenrick Fisher who was Jordan and Evermann's colleague at Stanford and the “V” is assumed to be a typo.
Hippocampus guttulatus, commonly known as the long-snouted seahorse and in Great Britain as the spiny seahorse, is a marine fish belonging to the family Syngnathidae, native from the northeast Atlantic, including the Mediterranean.
The great seahorse, also known as Kellogg's seahorse is a species of fish in the family Syngnathidae. It is one of the largest of the 54 species of seahorse.
The bullneck seahorse is a pygmy seahorse in the genus Hippocampus. This seahorse has never been found in the wild, and little is known about its natural habitat. The only known specimens were collected on the coast of Eden, Australia. It is thought to live in sand beds at the bottom of the ocean, "64 - 100 meters below sea level" possibly wrapping its prehensile tail around gorgonian corals. The seahorse is among the 25 “most wanted lost” species that are the focus of Re:wild's “Search for Lost Species” initiative.
The slender seahorse or longsnout seahorse is a species of fish in the family Syngnathidae that usually inhabits subtropical regions.
The hedgehog seahorse is a species of fish of the family Syngnathidae. It inhabits coastal waters from India and Sri Lanka to Taiwan and northern Australia. It is threatened by overfishing, as both targeted catch and bycatch. This species is ovoviviparous, with males carrying eggs in a brood pouch before giving birth to live young.
Hippocampus whitei, commonly known as White's seahorse, New Holland seahorse, or Sydney seahorse, is a species of marine fish of the family Syngnathidae. It is thought to be endemic to the Southwest Pacific, from Sydney, New South Wales and southern Queensland (Australia) to the Solomon Islands. It lives in shallow, inshore habitats, both natural and anthropogenic. This species is ovoviviparous, with males brooding eggs in a brood pouch before giving birth to live young.
The zebra seahorse is a species of fish in the family Syngnathidae. It is endemic to northern Australia.
The spiny seahorse, also referred to as the thorny seahorse, is a small marine fish in the family Syngnathidae, native to the Indo-Pacific area. It is classified as a Vulnerable species by the IUCN.
Hippocampus pontohi, also known as Pontoh's pygmy seahorse or the weedy pygmy seahorse, is a seahorse of the family Syngnathidae native to the central Indo-pacific. Named after Hentje Pontoh, the Indonesian dive guide from Bunaken (Manado) who first brought these pygmy seahorses to attention.
Hippocampus debelius, commonly known as the softcoral seahorse, is a species of marine fish of the family Syngnathidae. It is known from only two specimens collected from the Gulf of Suez in the Red Sea, at depths of 15–30 metres (49–98 ft). Individuals were found associated with soft corals. Although little is known of this species, it is expected to feed on crustaceans, similar to other seahorses. It is also expected to be ovoviviparous, with males carrying eggs in a brood pouch before giving birth to live young.
The Japanese pygmy seahorse is a Japanese species of seahorse in the family Syngnathidae. It is also sometimes known as the Japan pig.
