Identification of Demersal and Pelagic Eggs

Oviparous fishes classified into demersal spawners and pelagic spawners, the eggs they extrude are either demersal (on the bottom) or pelagic (above the bottom, and often at or near the surface). Common characteristic of eggs are tabled below.

Characteristic                                    Demersal                    Pelagic

Usual Size                                           > 1 mm                        ≤ 1 mm

Specific Gravity                                  greater                          less

Envelope                                            thicker                          thinner

Color                                                 opaque, colored             transparent

Amt. of Yolk                                       large                            small

Period of Dev. (Temperate)                  longer                           short

Parental Care                                      common                       none

Fecundity                                           low                              great (>1 million)

Larvae                                               swim/feed @ once         float/yolk sac

Dispersal                                            probably low                 probably high