Pandaka pygmaea, the dwarf pygmy goby, (also known as the Philippine goby[2]) is a tropicalfreshwater fish of the familyGobiidae. It is one of the smallest fish in the world by mass, and is also one of the shortest freshwater fish. Mature males can reach up to 1.1 centimetres (0.43 in) SL, while the females can grow up to 1.5 centimetres (0.59 in) SL. Average weight is from 4 to 5 milligrams (0.00014 to 0.00018 oz). It is known as bia and tabios in the Philippines.[3][4][5]
Dwarf pygmy gobies survive in demersal, freshwater, brackish and marine water environments at a pH ranging from 7.0 – 8.4, a dH range of 30, and at tropical temperatures measuring from 24 to 30 °C (75 to 86 °F).[3][4][5]
Appearance and anatomy
A colorless and nearly transparent species, the dwarf pygmy goby has a moderately elongated and robust body. Males are slender with nearly straight dorsal and ventral profiles, while the females appear stouter with the dorsal profile slightly curved, the belly protuberant, and the ventral outline strongly arched.[3][4][5]
The head of the P. pygmaea is large and blunt. The head and nape are naked. The upper and lower profiles converge and are pointed if viewed from the sides. The head is characteristically broader than deep. The head is very short, broad and rounded. The mouth is very oblique, with a projecting lower jaw and chin. The posterior angle of the maxillary extends beneath the anterior part of the eye, up to the middle of pupil. It possesses two rows of teeth in each jaw. The outer row of teeth inside the upper jaw is larger and more widely spaced, while the inner row is characteristically minute. The first dorsal fin is low, much in advance of the second dorsal fin but not reaching the second dorsal fin when depressed. The pectoral and ventral fins are pointed, with the latter about as long as the former or longer. The anal papilla is very short and rounded in females, but is longer and very slender in males.[3][4][5]
P. pygmaea have dark spots, which forms 4 cross-bands, over the sides of its body. The bases of the fins are heavily pigmented, except for the ventral fins. It has 22 to 25 scales in longitudinal series.[3][4][5]
Pandaka pygmaea was once portrayed on a Philippine ten centavo coin where, uniquely for a wildlife portrayal on coinage, it is depicted at life-size. The genus name is derived from the Filipino word pandak, meaning "dwarf" or "short of stature".[6]
References
^World Conservation Monitoring Centre 1996. Pandaka pygmaea. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. <www.iucnredlist.org>. Downloaded on 13 September 2013.