Sand stargazers are blennioids;

perciform Perciformes (), also called the Percomorpha or Acanthopteri, is an order (biology), order or superorder of Actinopterygii, ray-finned fish. If considered a single order, they are the most numerous order of vertebrates, containing about 41% of a ...

marine

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

of the family Dactyloscopidae. Found in temperate to tropical waters of

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and

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; some may also inhabit

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environments. The giant sand stargazer (''Dactylagnus mundus'') is the largest at 15 cm in length; all other species are under 10 cm. These blennies are named well: sand stargazers have protruding eyes on the top of their heads, fixed in an upward gaze, and may be on stalks. Their large mouths are also upturned. The dorsal fin is long and may or may not be continuous, with seven to 23 spines; the pelvic fins are situated below the throat and possess one spine. The anal fin is equally long and flowing. The mouth is fringed, and like the upper edge of the operculum (the gill cover), this fringe is divided into finger-like structures. The body is greatly elongated, and coloration is generally drab. As their name would suggest, sand stargazers spend most of their time buried in sandy substrates waiting for unsuspecting prey; only the eyes, nose and mouth are usually visible. Their mode of respiration is also unique among the blennioids, using a branchiostegal rather than opercular pump; this is thought to be an adaptation to their largely sedentary, obscured lives. Sand stargazers generally stay within shallow (< 10 m) intertidal zones in areas protected from surges. Small

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s and fish make up the bulk of the sand stargazer's diet. The family name Dactyloscopidae derives from the

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words ''daktylos'' meaning "finger" (a reference to the divided mouth and operculum fringes) and ''skopein'' meaning "to watch".

References

{{Taxonbar, from=Q2166073 Blenniiformes

See also

References