Fishes. 93 



class. Scorpaena has poisonous rays in its dorsal fin, but it is not 

 such a dangerous animal as the Sting -fish. A large species, of red 

 colour and with curious eyes, Scorpaena scrofa, will be seen in tank 

 Xr. 6. 



Allied in habit to the Sea-scorpion is the Goby, Gobius (Fig. 68), 

 a small, dark, ground-loving fish always to be seen at the bottom of 

 tanks 12 and 26. generally hidden in a crevice of the rock or in a bunch of 

 algae, but more fond of movement than Scorpaena. Under natural con- 

 ditions, in the spawning season they leave these hiding places and con- 

 struct a chamber covered in by the roots of the sea-weeds, where they 

 lay their eggs. The male fish is the architect of the nest, as is the 

 case with the Sticklebacks. At the entrance to the nest he waits to 

 entice females into it, and fertilizes the eggs as soon as they are laid. 

 Then he protects the spawn for about two months and wards off most 

 courageously all enemies. If a large number of females visit the nest, 

 he enlarges it and provides it with several exits ', this has also been 

 observed in the Aquarium on some occasions. 



The numerous species of the Blennies, Blennius, are small, very 

 agile, predatory fishes which live in large troops in those parts of the 

 coasts, which are covered with sea-weeds. Their mobile bodies are 

 continuously darting about and, should danger threaten, they disappear 

 at once into some hiding place. Their curiosity and "cheek" is extra- 

 ordinary, and causes them to snap at everything, and to annoy whatever 

 sannot protect itself. They nibble off the gills of the tubicolous worms, 

 they make dashes for the eyes of crabs and fishes, and they worry the 

 ascidians till the latter die. So they go on with all helpless animals. 

 The finest and largest form is the Butterfly-6sh, Blennius ocellaris 

 (Fig. 158), which possesses a large black eye-like spot on each side of 

 its dorsal fin. 



Hidden away similarly among the rocks we find the Heckling. Mo- 

 tella i^Fig. 151), which belongs to the family of the Cods. 



The transition from these fishes, tied more or less to the bed of 

 the sea, to the freely swimming fishes is formed by some good swimmers, 

 which, nevertheless, have a preference for the bottom or the coasts and 

 at times remain stationary like the previous forms, at other time swihi- 

 ming for considerable distances. To this group belong several species 

 of Gurnards, Trigla (Fig. 75). The Gurnards are remarkable on ac- 

 count of the peculiar grunting sound they emit when taken out of the 

 water. It is said not to be a real vocal sound, but only a frictional 

 noise produced by the rubbing of certain hard plates of the gill-cover 

 against underlying parts. They have also a peculiar way of "walking" 

 about on the sand by means of the free rays of their pectoral fins 

 which are destitute of membrane), the so-called "fingers". The hinder 

 part of the pectoral fins is very large and usually brilliantly coloured 

 and enables the fish to leap out of the water. They are predatory fish, 

 with a widely opening mouth, which will gulp down tremendous 

 morsels. 



A near ally is the Flying Gurnard. Dactylopterus (Fig. 77;. which, 

 however, in spite of its name does not appear to use its large pectoral 



