''Equulites popei'', Pope's ponyfish, is a species of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

, a

ponyfish Leiognathidae, the ponyfishes, slipmouths or slimys / slimies, are a small family of fishes in the order Perciformes. They inhabit marine and brackish waters in the Indian and West Pacific Oceans. They can be used in the preparation of ''bagoong' ...

from the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Leiognathidae Leiognathidae, the ponyfishes, slipmouths or slimys / slimies, are a small family of fishes in the order Perciformes. They inhabit marine and brackish waters in the Indian and West Pacific Oceans. They can be used in the preparation of ''bagoong' ...

. It has a wide

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

distribution which extends from the

Red Sea The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; T ...

east to the western Pacific Ocean. It has entered the Mediterranean as a Lessepsian migrant. It was formerly considered to be synonymous with the elongate ponyfish ('' Equulites elongatus'').

Description

''Equulites popei'' differs from the other members of the ''E. elongatus''

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

by having an eye diameter which is 82–137% of the length of the head to the rear of the eye. In addition, the distance from pelvic fin insertion to the centre of anus is a third to a half of that from the pelvic fin insertion to origin of the

anal 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 se ...

. The upper flanks have large dark blotches which occasionally create up to 2 ring markings and there are sometinmes up to 5 dark spots which are less than 50% of the diameter of the pupil. The head and lower flanks and belly are nearly a uniformly silvery white. The tip of the snout is blackish. The upper rear edge of the gill cover is light yellow. The upper flanks and back are silvery brown interspersed with dark blotches. The pectoral fin is pale yellow, there are black lines along the rays of the

caudal 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 se ...

which has a dark margin and all of the other fins are colourless. The maximum recorded

total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ...

is .

Distribution

''Equulites popei'' has an

distribution. Its range extends from the Red Sea and the coast of

East Africa East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa: Due to the historical ...

east to the Philippines and north to Japan. It was recorded as ''E. elongatus'' for the first time in the Mediterranean Sea off Israel in 2011, and more recently off Lebanon and Turkey where it remains rare.Atlas of Exotic Fishes in the Mediterranean Sea (Equulites popei). 2nd Edition. 2021. 366p. CIESM Publishers, Paris, Monaco.https://ciesm.org/atlas/fishes_2nd_edition/Equulites_popei.pdf

Habitat and biology

''Equulites popei'' is found in shallow waters, where it is normally encountered in schools close to the bottom. It feeds mostly on small

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 ...

polychaetes Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made ...

and

algae 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 mic ...

Taxonomy

''Equulites popei'' was first formally described in 1932 as ''Macilentichthys popei'' by the

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 ...

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish ( Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 33,400 species of fish had been described as of Octobe ...

Gilbert Percy Whitley (1903–1975) with the type locality given as

Kagoshima , abbreviated to , is the capital city of Kagoshima Prefecture, Japan. Located at the southwestern tip of the island of Kyushu, Kagoshima is the largest city in the prefecture by some margin. It has been nicknamed the "Naples of the Eastern wor ...

, Japan. Whitley did not specify the identity of the person honoured in its specific name but since he was replacing the preoccupied name ''elongatus'' given to this species by the

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

ichthyologists

Hugh McCormick Smith Hugh McCormick Smith, also H. M. Smith (November 21, 1865 – September 28, 1941) was an American ichthyologist and administrator in the United States Bureau of Fisheries. Biography Smith was born in Washington, D.C. In 1888, he received a Doc ...

(1865–1941) and Thomas E.B. Pope then it is likely that Pope was being honoured. Until recently ''E. popei'' was considered synonymous with ''E. elongatus'' but ''E. elongatus'' is now considered a species complex with ''E. popei'' and the Red Sea elongate ponyfish ('' Equulites aethopos'').

References

{{Taxonbar, from=Q99853190 popei Fish of the Indian Ocean Fish of the Pacific Ocean Fish of the Mediterranean Sea Fish described in 1932 Taxa named by Gilbert Percy Whitley