Apeltes quadracus (Four-spined Stickleback). 1887. Sticklebacks; Four-spined stickleback.

Descrission:

Apeltes quadracus (Four-spined Stickleback). Fig.22 Embryo in the egg, showing the asymmetrically disposed vitelline vessels; figs. 23 & 24 Other views of the same stage, showing the lateral position of the heart; Fig.25 Dorsal view of a recently hatched embryo, showing the distribution of the brown pigment blotches on the median line and the symmetry in the distribution of the vascular channels on the dorsal side of the yelk; Fig.26 Side view of the same stage, showing the pigmentation and vascular loops in the dorsal fin-fold