naupliar eye

Relatively simple, median eye, typically consisting of 3 photoreceptor units (up to 7 in taxa where it persists in the adult) and first appearing in the nauplius larval stage. Thought to be a primitive (defining) feature of the Crustacea; it is secondarily reduced or lost in many taxa [Brusca and Brusca, 2002].

Unpaired median eye found in naupliar larval stages and commonly in more mature stages as well. (Syn. median eye) [Moore and McCormick, 1969].

Unpaired median eye, common in nauplii and many adult crustaceans; structure simple, consisting of 1 to few light-sensitive cells. (Syn. median eye) [McLaughlin, 1980].

(Order Cladocera):

Small median photosensitive organ located ventrally on head between mouth and compound eye. (Syn. median eye, ocelus) [Stachowitsch, 1992].

(Order Notostraca):

Small median photosensitive organ located in front of compound eyes on sloping anterior of carapace; consists of four cups. (Syn. median eye) [Stachowitsch, 1992].

(Order Diplostraca):

Small median photosensitive organ located ventrally on rostrum of head. (See also compound eye). (Syn. median eye) [Stachowitsch, 1992].

(Order Anostraca):

Unpaired median photosensitive organ located somewhat posteriorly to antennules on anterior part of head; relatively small, consisting of three (two lateral, one ventral) cups. (See also compound eye) [Stachowitsch, 1992].

(Subclass Mystacocarida):

Ocellus [Stachowitsch, 1992].

(Class Ostracoda):

Single medial anterior eye, normally composed of 3 eye cups, has reflecting tapetal layer. (Syn. medial eye) [Cohen, Peterson, and Maddocks, in press].