GENETIC LINEAGE AND ENVIRONMENTAL CONDITIONS AS DRIVERS OF CHROMATOSOME VARIATION IN THE ANCHI ALINE SHRIMP HALOCARIDINA RUBRA HOLTHUIS, 1963 (CARIDEA: ATYIDAE)

• Published in: Journal of crustacean biology 2014-01, Vol.34 (5), p.647-657
• Main Authors: Vaught, Rebecca C, Havird, Justin C, Santos, Scott R
• Format: Article
• Language: English
• Subjects: Atyidae; Caridea; Decapoda; Halocaridina rubra
• ISSN: 0278-0372; 1937-240X
• DOI: 10.1163/1937240X-00002255

Color variation among and within crustacean species is primarily due to morphological and physiological differences in specialized cells called chromatophores. Within Atyidae, individuals of Halocaridina rubra Holthuis, 1963, which is endemic to anchi aline habitats (coastal ponds of mixohaline water under marine and terrestrial influences) of the Hawaiian Islands, range from bright red to nearly translucent in color. While H. rubra encompasses (at least) eight genetically diverged lineages based on analyses of mitochondrial genes, whether this phenotypic variation in coloration correlates to genetic background or if it statistically differs between lineages is unknown. Furthermore, if such properties in H. rubra exhibit plasticity under the environmental extremes that can be encountered in anchialine habitats has not been determined. Using previously published protocols for another atyid species, chromatosomal morphology and chromatic properties were quantified and statistically analyzed from 240 individuals of H. rubra, representing seven of the eight genetic lineages as well as one naturally mixed population (n = 30 per group), maintained under standardized laboratory conditions for >6 years. Analogous analyses were also conducted on animals before and after exposure to environmental extremes, including anoxia, desiccation, decreased salinity and high and low temperatures. Overall, the genetic lineages of H. rubra statistically differed from one another in varying numbers of chromatosomal properties while exposure to environmental extremes also elicited significant changes. Furthermore, these properties statistically differed among body parts of H. rubra in a manner inconsistent with previous studies. Notably, data on chromosomal properties generated via a streamlined protocol were well correlated with those from the previously published approach utilized here, suggesting such analyses for H. rubra (or other crustacean/atyid species) might be successfully conducted under field settings.