Friday 15 July 2011

Fish Identification, Gobies.



Gobies are possibly the most difficult group of fish to identify...

starting with one of the easier...

The Rock Goby

Like all gobies the Rock Goby has two separate fins on top rather than the one continuous dorsal fin of the blennies. It is easy to identify by the cream coloured fringe to the first dorsal fin, ( we refer to them as custard tipped gobies, it seems a more accurate descriptor than rock )

Rock Goby ( Gobius paganellus )


Colour is not a good way to identify fish, as can be seen with the variation here, the male often changes to a dark, almost black, colouration when breeding
I read that the female has a cream fringe and the male, orange. the sex of gobies is of interest to gobies but not to many anglers. Catch them in rocky or weedy places close to structures like piers and walls. They can be caught in stuaries in brackish water.

 A little section of worm on a size 4 or smaller hook fished close to the bottom or on the wall surface will do the job, but they will take about anything, they are not fussy eaters.

The 'pelvic' fins are very far forward underneath and form a sort of suction cup by which the goby will cling on to smooth surfaces. Most fish caught will be 12cm or less.

The Black Goby




                                                         Black Goby, (Gobius niger) 


Black Goby, (Gobius niger) showing the specialised pelvic fins.

The Black Goby is fairly easily identified in the breeding season; the last few rays of the first dorsal fin are very elongated, however the fin does not show this feature all year. The black refers to the dark blotches on the flanks of the fish, not the overall colour which can vary from sandy to dark brown, the breeding males can be almost black . The first example shown was caught in the weed and rough at Hobb's Point and the second over eelgrass off The Pleasure Pier, Weymouth. It seems to prefer more silty and less rocky places than the Rock Goby.

for further reading, The Aquarium Project is a good reference site





to be continued.

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