Apposition compound eyes of Spongicoloides koehleri (Crustacea: Spongicolidae) are derived by neoteny

Abstract

Apposition compound eyes of Spongicoloides koehleri (Crustacea: Spongicolidae) are derived by neoteny Wedding shrimps, Spongicoloides koehleri, spend the adult phase of their life cycle within the cavity of a hexactinellid sponge. Although there is little light at the depths at which the sponges are found, the shrimps do not use the highly sensitive reflecting superposition optics commonly found in other shrimp-like decapods. Instead they have apposition eyes which are virtually free of shielding pigment. It is proposed that this is due to the paedomorphic retention of the larval optics through the process of neoteny.

Treatise on Zoology - Anatomy, Taxonomy, Biology. The Crustacea, Volume 9 Part A

“…Stenopodideans have reflecting superposition eyes (Richter, 2002), but an interesting exception is found in Spongicoloides koehleri. Gaten (2007) found this species to have apposition compound eyes, which he believed were derived from neoteny. These unpigmented eyes with circular facets are very similar to the eyes of larval decapod crustaceans, but in the adults of Spongicoloides koehleri, their eyes lacked a proximal shielding pigment, giving a further loss of resolution.…”

Exceptional Variation on a Common Theme: The Evolution of Crustacean Compound Eyes

“…Fig. 7), adult shrimps of the family Spongicolidae may possess apposition eyes produced by neoteny (Gaten 2007). Interestingly, mysids brood their young, so the juveniles are never planktonic; yet developing mysids also have apposition compound eyes that transform to refracting superposition eyes in the adults (Nilsson et al 1986).…”