Adaptive color vision in Pullosquilla litoralis (Stomatopoda,Lysiosquilloidea) associated with spectral and intensity changes in light environment

Abstract

Some stomatopod crustacean species that inhabit a range of habitat depths have color vision systems that adapt to changes in ambient light conditions. To date, this change in retinal function has been demonstrated in species within the superfamily Gonodactyloidea in response to varying the spectral range of light. Intrarhabdomal filters in certain ommatidia within the specialized midband of the eye change spectrally, modifying the sensitivity of underlying photoreceptors to match the spectrum of available light. In the present study, we utilized Pullosquilla litoralis, a member of the superfamily Lysiosquilloidea that also has a wide depth range. Individuals were placed within one of three light treatments: (1) full-spectrum, high-intensity 'white' light, (2) narrow-spectrum 'blue' light and (3) full-spectrum, reduced-intensity 'gray' light. After 3 months, the intrarhabdomal filters in Row 3 ommatidia of the midband in blue-and gray-light-treated animals were short-wavelength shifted by 10-20 nm compared with homologous filters in animals in white-light treatments. These spectral changes increase the relative sensitivity of associated photoreceptors in animals that inhabit environments where light spectral range or intensity is reduced. The adaptable color vision system of stomatopods may allow animals to make the best use of the ambient light occurring at their habitat regardless of depth. The major controlling element of the plasticity in lysiosquilloid stomatopod color vision appears to be light intensity rather than spectral distribution.

Evolution of anatomical and physiological specialization in the compound eyes of stomatopod crustaceans

“…The remaining filter location, row 3 proximal, is fairly conservative in the number of classes observed among species, containing only three (Fig.9). However, like its mate in the row 3 distal position, this filter can vary within a species, sometimes even in a single retina (Cronin et al, 2001;Cheroske et al, 2003;Cheroske et al, 2006).…”

“…Unlike the invariant filters in row 2, in many mantis shrimp species the row 3 filters in both the distal and the proximal location are 'tunable' within an individual based on the available environmental light (Cronin et al, 2001;Cheroske et al, 2003;Cheroske et al, 2006). Because of this flexibility, a large set of diverse filters is not required here to tune the underlying photoreceptors.…”

Evolutionary variation in the expression of phenotypically plastic color vision in Caribbean mantis shrimps, genus Neogonodactylus

“…Some retinal classes of ommatidia contain colored intrarhabdomal filters that narrowly tune the sensitivities of underlying photoreceptors (Marshall et al 1991;Cronin et al 1994a). Particular species that inhabit a wide depth range (from shallow intertidal to > 20 m) have evidenced phenotypically plastic modification of their color vision system, produced by changes in the colored filters in response to varying light environments (Cronin et al 2001;Cronin and Caldwell 2002;Cheroske et al 2003). Stomatopod post-larvae maintained in laboratory lighting approximating shallow water (full-spectrum, white) or deep water (narrowspectrum, blue) shift their spectral sensitivities to improve the match to surrounding light conditions in as little as a few weeks (Ibid.…”

Ultraviolet filters in stomatopod crustaceans: diversity, ecology, and evolution

“…This suggests that MAA filters are incorporated into the crystalline cones early in development, perhaps as soon as the adult eye develops during late larval stages. Additional observations are required from larval developmental stages, as well as longer-term experiments where postlarvae are reared in variable ambient UV light environments similar to previous studies on the longwavelength colored filters in the main rhabdoms (Cheroske et al, 2003;Cronin et al, 2001). …”

“…Some species even tune the absorption properties of these filters by varying the lengths of the filters or altering the composition of the pigments they contain in order to best suit their spectral environment (Cheroske et al, 2006(Cheroske et al, , 2003Cronin et al, 1994bCronin et al, , 2000Cronin et al, , 2001. Considering the high degree of variability in the absorbance characteristics of these longwavelength filters, we were curious to learn how the UV filters vary across species.…”