486 FISHES. 



near the coasts of all temperate and tropical regions. Geo- 

 logically they appear first in the chalk. 



Gobi us. — Body scaly. Two dorsal fins, the anterior generally 

 with six flexible spines. Ventral fins united, forming a disk 

 which is not attached to the abdomen. Gill-opening vertical, 

 moderately wide. 



The " Gobies '' are distributed over all temperate and 

 tropical coasts, and abundant, especially on the latter, l^early 

 three hundred species have been described. They live espe- 

 cially on rocky coasts, attaching themselves firmly with their 

 ventrals to a rock in almost any position, and thus withstand- 

 ing the force of the waves. Many of the species seem to 

 delight in darting from place to place in the rush of water 

 which breaks upon the shore. Others live in quiet brackish 



iff' The males of somespecies 



Fig. 220.— Gobius lentiginosus, from Construct nests for the 

 New Zealand. eggs, which they jeal- 



ously watch, and defend even for some time after the young 

 are hatched. Several species are found on the British coast : 

 G. niger, paganellus, auratus, minutus, rutJiensparri. Fossil 

 species of this genus have been found at Monte Bolca. 



A very small Goby, Zatrunculus pellucidus, common in 

 some localities of the British Islands and other parts of 

 Europe, is distinguished by its transparent body, wide mouth, 

 and uniserial dentition. According to E. Collett it offers 

 some very remarkable peculiarities. It lives one year only, 

 being the first instance of an annual vertebrate. It spawns 

 in June and July, the eggs are hatched in August, and the 

 fishes attain their full growth in the months from October to 

 December. In this stage the sexes are quite alike, both 



