DEVELOPMENT AND LIFE HISTORY OF SOME TELEOSTS 
577 
the eye. Although the tentacle is variable in length among individuals of the same 
sex, it is rarely as long as the eye in adult females, whereas it always exceeds the 
length of the eye in adult males. Males differ from the females in external structure, 
furthermore, in having fleshy expansions or hoods, opening forward, attached to the 
two anal spines, and the fin itself is preceded by a low elliptical membranous hood, 
opening backward. Females have a distinct genital papilla, at least during the 
breeding season, which is not evident in the males (fig. 74). 
The shallow water areas with rather hard, often somewhat shelly, bottom sup- 
porting growths of plants, sponges, ascidians, hy droids, etc., are the common summer 
habitat of the adults. The shallow areas are deserted during the winter when speci- 
mens occasionally are taken in the deeper channels and in holes, where the species 
also occurs sparingly during the summer. 
It is a game little fish and like its relative, Chasmodes bosguianus, it fights when 
handled. It will seize the skin (its mouth being too small to catch more than the 
skin) of a man’s hand and hold on bulldog fashion, allowing itself to be lifted by its 
grasp. However, its jaws are not strong enough to inflict a wound. 
Figure 74 . — Hypsoblennius hentz. Adult male 96 mm long. Note membranous expansions attached to the anal spines. 
Color assimilation is well developed in this blenny. It is hardy, stands handling, 
and endures confinement in small aquaria very well and, therefore, it constitutes a 
fairly favorable subject for the study of its reactions to various color stimuli. 
The species no doubt is preyed upon to a limited extent by various predatory 
fishes. It is not abundant enough locally to be of much importance even as a forage 
fish, and of course it is too small to be of direct commercial use, as 100 mm (4 inches) 
is near the maximum size attained. 
The figures of the developing egg and the newly hatched larva are based on 
living material. The other illustrations were prepared from preserved specimens. 
SPAWNING 
Eggs of several sizes are present in the ovary at one time, just as in the other 
local species of blenny, suggesting a long spawning season, as well as repeated spawn- 
ing. This expectation is substantiated by the presence of fry less than 5.0 mm in 
length in the tow from May 13 (1930) to September 13 (1927). The young of this 
species were never as abundant in collections as those of HypLeurochilus geminatus. 
They were taken in fair numbers, however, from about the middle of May to the end 
