PLANKTON OF THE WOODS HOLE REGION 165 
he believed to be necessary, for the milt rises and is likely to be lost before the eggs 
can be fertilized. The eggs are usually quite opaque and heavily laden with yolk. 
By being grouped in large bunches they are not so easily preyed upon by the bottom- 
feeding animals, although no doubt many are lost in this way. The eggs are com- 
paratively fewer in number and have a longer incubation period. 
Young fish of this group are often just as numerous in surface collections as 
those hatching from pelagic eggs, for they usually hatch in a much more advanced 
stage, thus greatly reducing the mortality. 
Gadus callarias and Pholis gunnellus, characteristic members of the spring plank- 
ton, are excellent representatives of these two groups. The former emerge from the 
e eo 
E z 
Pautogolabrus adspersus pF 
Tautoga onitis 
Prionotus carolinus 
Stenotomus chrysops 
Jule 
Sepe 
Octe 
NOVe 
Dece 
Brevoortia tyrannus 
Syngnathus fusous 
Spheroides maculatus 
Lophopsetta maculata 
Merluccius bilinearis 
Poronotus triacanthus | 
‘Menidia menidia notata ‘ 
Urophysis spe SBue wea : 
-Leptocephalus Elops ? 
Rhinonems cimbrius 
Heplatessoides 
Myoxocephalus aeneus 7? 
Microgadus tomcod 
Fic. 65.—Occurrence of fishes in surface collections from June to Decemper, 1922 
egg in a helpless condition and for some time are tossed about at the mercy of the 
waves as delicate little transparent larve. (The black chromatophores arrange 
themselves in vertical bands and may camouflage the young fish in much the same 
way that similar designs served to protect our ships during the late war.) The 
other species (Pholis gunnellus) is never found in an entirely helpless condition. 
The young, which are much farther advanced than those of the cod when they 
appear in surface collections, are always very lively and swim rapidly toward the 
light when placed in a glass tray. (The larval cod were always dead when removed 
from the nets.) Copepods were always found in the intestines of even the smallest 
specimens. This is further evidence of the activity of this species in its very early 
pelagic existence. The eggs are laid on the bottom in a compact mass and are 
guarded by the adult fish until hatched. 
