Nemateleotris helfrichi, Helfrich's Dartfish, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

dartfish Dartfishes are a group of fish, formerly considered to be a subfamily, Ptereleotrinae, of goby-like fishes in the family Microdesmidae of the order Gobiiformes, Authorities now consider the species in the family Microdesmidae are within the Gobi ...

native to the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

Description

They are small fishes that grow to a maximum length of . They have bright yellow head with purple forehead with purple and white shades on body.Saltwater Aquarium Fish for Marine Aquariums: Firefish, Helfrichi
/ref> They have 7 dorsal spines 28-31 dorsal soft rays and 1 anal spine 26-28 anal soft rays.Nemateleotris helfrichi, Helfrichs' dartfish : aquarium
/ref>

Distribution and Habitat

They are present in the

between latitudes 16°N and 28°S. Their range extends from

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

Tuamotu Archipelago The Tuamotu Archipelago or the Tuamotu Islands (french: Îles Tuamotu, officially ) are a French Polynesian chain of just under 80 islands and atolls in the southern Pacific Ocean. They constitute the largest chain of atolls in the world, extendin ...

. They prefer deeper waters than other

Nemateleotris ''Nemateleotris'' is a genus of dartfishes native to the Indian and Pacific oceans. Species There are currently four recognized species in this genus: * '' Nemateleotris decora'' J. E. Randall & G. R. Allen, 1973 (Elegant firefish) * '' Nemate ...

. They are found swimming a few meters above the water bed. They are found at a depths between and are rarely found above .

Diet

They are

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

. ''N. helfrichi'' mainly feed on

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

amphipods 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 descri ...

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

, small

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 ...

and

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...

larvae.Helfrichi Firefish, Species Profile, Hobbyist Guide, Care Instructions, Feeding and more.
/ref> They are said to lose their bright colour if their dietary requirements are not met.

Behaviour

The species is

monogamous Monogamy ( ) is a form of Dyad (sociology), dyadic Intimate relationship, relationship in which an individual has only one Significant other, partner during their lifetime. Alternately, only one partner at any one time (Monogamy#Serial monogamy, ...

and are usually found in pairs.Whiteman, E.A. and I.M. Côté, 2004. Monogamy in marine fishes. Biol. Rev. 79:351-375. They are territorial and will fight with

conspecifics Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organis ...

unless they are a pair.FreshMarine.com - Helfrich's Firefish Goby - Nemateleotris helfrichi
/ref> The species is shy and hides in small caves when threatened.

In the aquarium

Due to their bright colour they are very popular as a marine aquarium fish. They are also more delicate and rare form than other more common firefish species (as evidenced by their price) and should be kept by marine-aquarists of intermediate expertise or higher.

Name

The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

honours Philip Helfrich, an Emeritus Director and Researcher,

Hawaii Institute of Marine Biology Hawaii ( ; haw, Hawaii or ) is a U.S. state, state in the Western United States, Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is ...

(

University of Hawaii A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, th ...

), and the director of the Eniwetok Marine Biological Laboratory, who collected some of the first specimens of this species.

References

{{Taxonbar, from=Q1602125 helfrichi Tropical fish Fish described in 1973 Taxa named by John Ernest Randall Taxa named by Gerald R. Allen