Panamic Stargazer, Dactylagnus parvus
Panamic Stargazer, Dactylagnus parvus. A very rare species caught in the surf zone off the beach with a water bucket, Todos Santos, Baja California Sur, June 2013. Length: 6.2 cm (2.4 inches).
The Panamic Stargazer, Dactylagnus parvus, is a member of the Sand Stargazers or Dactyloscopidae Family that is also known as the Dwarf Stargazer and in Mexico as miraestrellas panámica. Globally, there are three species in the genus Dactylagnus, of which two are found in Mexican waters, both in the Pacific Ocean.
The Panamic Stargazer has an elongated cigar-shaped body that tapers gradually to the tail. They are light brown with brown markings including a large blotch between their eyes, several smaller blotches behind their eyes, and 8 or 9 bars along their upper back. Their snout is unpigmented. Their caudal fin has 2 or 3 faint bars, their dorsal fin is irregularly streaked, and their pectoral fins have 3 broken bars. They have a large head that is deep and bluntly rounded at the front, tubular nostrils, and an upturned mouth with a protruding lower jaw. Their eyes are on top of the head and not stalked. Their anal fin has 2 spines and 29 to 34 rays; their dorsal fin is continuous, originates before the anal fin, and has 8 to 11 spines and 28 to 34 rays; and, their pectoral fins have a broad base with 12 to 14 rays. Their body is covered with small scales and the lateral line is continuous.
The Panamic Stargazer is a solitary benthic coastal demersal species that is normally found submerged in substrate such as beaches, sand bottoms, and soft bottom habitats in mangroves and estuaries at depths up to 6 m (20 feet). They reach a maximum of 6.2 cm (2.4 inches) in length, with the fish photographed above establishing this maximum length. They are ambush predators that lie in wait with only their eyes exposed and consume small invertebrates and fish. The Panamic Stargazer is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.
The Panamic Stargazer is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found from Magdalena Bay, Baja California Sur southward along the southwest coast of Baja and from Acapulco, Guerrero southward along the coast of the mainland to Guatemala.
The Panamic Stargazer can be confused with the Giant Stargazer, Dactylagnus mundus (no saddles on back; 35 to 41 anal fin rays; dorsal fin origin behind anal fin origin).
From a conservation perspective the Panamic Stargazer is currently considered to be of Least Concern with stable, widely distributed populations. Long term they are prone to habitat loss, including mangroves, from coastal development. They are small in stature and seldom seen by humans and are of limited interest to most.