GOBIES. 181 



The Gobies proper (gcuus Gobius) are common in shallow coastal ( J "7- 

 waters around the British Isles and the Continent of Europe, the 

 British forms including the Common Goby, Gobius minutus, 801, 

 the Rock Goby, Gobius paganellus, 796, the Painted Goby, Gobius 

 jpictus, 802, the Spotted Goby, Gobius ruthensparri, 800, and fig. 85. 

 and the Black Goby, Gobius niger, 799. The last species is mostly 

 of an ashen grey colour, but when excited, as when in pursuit of 

 its prey or when caught in a net, it changes to a dark smoke-colour. 

 The Gobies are interesting on account of their breeding habits. 

 The eggs are fixed by the female to the under surface of stones or 

 weeds (see 1147, in Cabinet-case 29), or beneath a simple nest 

 made out of shells of the Cockle or Limpet, or a Crab-shell. The 



r£for^ 



Fig. 85. — Spotted Goby, Gobius ruthensparri. 

 (From Boulenger, Cam. Nat. Hist., vii, 1904, after Holt and Byrne). 



male is more brilliantly coloured than the female, and guards the 

 eggs until they are hatched, remaining attached to the stone or 

 shell by its pelvic sucker. The White Goby, Aphiapellucida, 803, 

 has a transparent and colourless body, and was formerly supposed 

 to be the fry of a larger fish. It does not live more than a single 

 year. The Walking-fish or Jumping-fish, Periophthalmus koel- 

 reuteri, 804, is common on the mud-flats at the mouths of rivers 

 in tropical Africa, Asia and Australia. It jumps about by the 

 exercise of its stout pectoral fins and appears a curious object 

 with its head raised and its two bulging eyes set close together 

 near the top of the head. 



