P.novemradiatus ranges from east India and Thailand to the Philippine, a distribution pattern similar to that of P.chrysospilos. This species prefers the shade within a mangrove forest, a habitat which is submerged only at the highest level of the tide. The body has a dusky pattern, mottled like a leopard, and with few bright spots (unlike most other Periophthalmus species that have brilliant spots). It can be distinguished from other species by the black coloration at edge of the opercle and abdomen.
The scientific name, novemradiatus, refers to the 9 spines of the first dorsal fin. |
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One of the features of P. novemradiatus is a mottled pattern of the whole body. The opercle's edge and abdomen are blackened.
It is difficult to see this species in the field unless it moves, because of its completely protective coloration which matches the pattern of wood and mud.
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Most individuals are seen around the tidepools (puddles) of a mangrove swamp. They are seldom observed along the coasts of rivers or the sea.
P. novemradiatus is sympatric to P. argentilineatus in Nypa palm forest of south Thailand (right picture).
They seem to like to be on land among the mangroves and do not spend a long time in the water. After observing them, I came away with the feeling that their home range is limited because they don't migrate long distances.
Perhaps they limit their home range because they are unsure whether there would be a puddle if they moved further on.
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| There are many orange-red sopts in both dorsal fins. Even the pectral fin and the spots of the caudal fin appear to be tangerine.
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Pelvic fins of
P.novemradiatus
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The pelvic fins are largely separate, like a bow knot. Unlike P. argentilineatus, they have a membrane (frenum) joining pelvic fin spines.
The pectoral fins are normally colorless, but sometimes become red in my aquarium when the mudskippers are excited. I have not yet seen such red pectoral fins in the field.
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