66 



BLIND VERTEBRATES AND THEIR EYES. 



It is thus seen that almost every nook available has been taken possession of 

 by these diminutive fishes. All of them have the two ventrals united along the 

 median line and a thin membrane stretched across their bases to form a pouch. 

 By appressing the ventrals and then raising them, a partial vacuum is formed in 

 this pouch and the fish is enabled to cling to any substance with which its ventral 

 happens to be in contact. In confinement the blind fish frequently utilizes the 

 surface of the water of an aquarium for a surface of attachment. 



All the species in the bay have the habit, if disturbed, of hiding in crab or 

 clam holes. Clevelandia will sit on its tail and pectorals until the hand is near it ; 

 then with a quickness which would do honor to a Johnnie Darter, with a flirt of 

 the tail and a stroke of the pectoral, it disappears into its hole, from which, how- 

 ever, it at once thrusts its head to await developments. Several of them frequently 

 take refuge in the same hole. 



Gillichthys is the largest of these gobies. About San Diego the young are 

 abundant throughout the year. The adult can be caught with hook and line in 

 quantities, especially just at the return of tide during summer. Toward their 

 spawning season they retire to their respective crab holes, and no morsel, how- 

 ever tempting, will lure them forth. At San Diego they begin to spawn about the 



Fig. 26. {a) Typhlogobius californiemis Steind. From base of Point Loma. 

 (6) Typklogobius about 25 mm. long. 



end of March. The young, when first observed, have but few color cells. They 

 are very active, jumping several times their own length if left dry in a watch crystal. 

 The young of this species but little resemble the adult. The maxillary does not 

 reach beyond the eye, the color is in more or less well-defined crossbars, and the 

 scales, which in the adult are cycloid, have several large teeth. 



Clevelandia is by far the most abundant of the gobies, and in fact the most 

 abundant of any fish in the bay of San Diego. They are found everywhere between 

 high and low water mark, and doubtless form an important item of the food of 

 the larger fishes. They spawn in the early part of May. The young rise to the 

 surface at night, and are then sometimes taken in the surface dredge. They can, 

 however, be procured more abundantly in the latter part of May in the pools left 

 at low tide about the piles of wharves. 



The most remarkable of the gobies is undoubtedly the blind one inhabiting 

 the crab holes under rocks at Point Loma. In its pink color and general appear- 

 ance it much resembles the blind fishes inhabiting the caves of southern Indiana. 

 Its peculiarities are doubtless due to its habits. The entire bay region is inhabited 

 by a carideoid crustacean which burrows in the mud, which, like the blind fish, is 

 pink in color. Its holes in the bay are frequented by Clevelandia, etc., while at 



