Pearse's mudskipper (Periophthalmus novemradiatus) or Indian dwarf mudskipper, is a species of mudskippers native to marine and brackish waters along the coasts of the Bay of Bengal. This species is amphibious, dwelling in intertidal areas. It can reach a length of 10 centimetres (3.9 in).

SHORT DESCRIPTION

• This species is sexually dimorphic. Males have a greatly elongated first spine on the first dorsal fin, which reaches the eighth element of the second dorsal fin when appressed. When preserved, the first dorsal fin is brown or black with a white distal edge and no spots.

• The margin of the first dorsal fin is concave in males and concave to straight in females. The second dorsal fin features two black bands, with a broader one located inframarginally and the other medially, along with black spots at the base of the membrane between the dorsal fin elements.

• The pelvic fin has a prominent frenum, and the inner rays are fused for more than half their length. The species typically has 9–11 dorsal spines, 112 soft dorsal rays, 1 anal spine, and 12–13 soft anal rays. The caudal fin usually has 15 segmented rays, with the first and last two rays unbranched.

• There are 62–67 lateral scale rows and 18–24 predorsal scales.

DISTRIBUTION

• Found around the coastlines of India, Myanmar, Thailand, Malaysia, the Phillipines and parts of northern Indonesia.

HABITAT

• Occurs mainly in estuarine mangrove swamps, where it lives on and around mudflats at the water’s edge.

• Some populations live in highly tidal areas, where the flats are only exposed at low tide.

• The fish emerge to forage during these periods, retreating underwater to their burrows when the water level begins to rise.

DIET

• This species feeds chiefly on small crabs, insects and other invertebrates in the wild but proves surprisingly adaptable in captivity.

SEXUAL DIMORPHISM

• Unconfirmed. Some specimens do appear significantly fuller-bellied at maturity and it’s possible that these are females. Certain individuals develop an extended first dorsal ray and this may be another indicator of sex.

REPRODUCTION

• In nature the males dig deep, turreted shafts in the mud in which it is thought that mating and brood care takes place.

• The natural environment of these fish is so complex that it is nearly impossible to replicate, making captive reproduction unlikely in the foreseeable future.