Sand Stargazer Family Photos and Information – Dactyloscopidae

The Sand Stargazer Family – Dactyloscopidae

There are currently two members of the Sand Stargazer or Dactyloscopidae Family, both from the Pacific, presented in this website:

Giant Stargazer, Dactylagnus mundus.

Panamic Stargazer, Dactylagnus parvus.

The Sand Stargazer or Dactyloscopidae Family, known as miraestrellas in Mexico, is a group of small-sized fish with the largest species having a maximum length of 15.0 cm (5.9 inches). There are forty-four global members placed in nine genera in the family and they are found in temperate and tropical waters of North and South America. There are twenty-four species found in Mexican waters, five in the Atlantic and nineteen in the Pacific.

The Sand Stargazers have elongated cigar-shaped bodies that taper toward the tail. They are generally a drab “sand color” (light tan) with darker blotches dorsally. They have a deep broad head with protruding eyes on top looking skyward, a large upturned mouth with skin flaps that function to keep sand out of their mouth, tubular nostrils, a protruding lower jaw, small minute teeth, and large gill openings. Their anal fin has two spines, 21 to 44 rays, and a long base. Their dorsal fin has a long base and is divided or continuous with 7 to 23 spines and 12 to 36 rays. Their pelvic fins are found under the throat and have free tips. Their lateral line is bent, high on the side of the body at the front, and extends to the caudal fin base. They are covered with large smooth scales.

The Sand Stargazers are generally poorly studied and little is known about their behavioral patterns. They live sedentary obscure lives in shallow coastal waters, normally out of the surge zone, and are seldom seen by humans. They spend most of their time buried in sand substrate with only their eyes and the top of their head exposed. This affords them protection from predation and allows them to exist as lie in wait ambush predators. They consume small invertebrates and fish. Reproduction is poorly understood but they do have a unique trait whereby males carry the eggs under their pectoral fins for extended periods of time. From a conservation perspective they are currently considered of Least Concern. They are prone to habitat loss, including mangroves, from coastal development.