THE INTRARHABDOMAL FILTERS IN THE RETINAS OF MANTIS SHRIMPS

The intrarhabdomal filters in the photoreceptors of compound eyes of 3 2 species of mantis shrimps (Crustacea: Stomatopoda), representing sev en families within the superfamilies Lysiosquilloidea and Gonodactyloi dea, were surveyed by microspectrophotometry of filters in fresh cryos ections of the retina. A total of up to four classes of filters exist in stomatopods: two each in Rows 2 and 3 of the midband. All lysiosqui lloid species lacked the proximal filter in Row 3; a few also lacked t he proximal Row 2 class. While most gonodactyloid species had all four possible classes, in some species the proximal filters of Row 3 and ( in one case) Row 2 were missing. In all, at least 11 distinct spectral classes of pigments were found. Absorption spectra suggested that the filter pigments were probably carotenoids or carotenoproteins, althou gh the distal filter of Row 3 was often exceptional, appearing to cont ain a mixture of pigments. While the types of pigments found in the fi lters of the various species generally followed taxonomic lines, numer ous exceptions were found that were apparently related to the ecologic al requirements of the various species.