Variations in host surfaces morphology and biology of ciliate epibionts explaining distribution pattern of epibionts in the invasive signal crayfish Pacifastacus leniusculus (Dana, 1852)

Abstract

The present paper reports the distribution of Epistylididae (Sessilida) epibiotic ciliates on the signal crayfish Pacifastacus leniusculus in relation to specialized structures of the host's exoskeleton for the first time. This species is known to maintain a relatively clean carapace, but it is sometimes overgrown by other organisms. Epibionts cover different parts of the signal crayfish body, mainly antennae, antennules, maxillipedes III and pereiopods with inner edges of chelae; however, some parts of the signal crayfish are not fouled. e.g. dorsal surfaces of the carapace and dorsal surfaces of chelae. Using scanning electron microscopy (SEM), topographies of different parts of the crayfish's exoskeleton were examined. Our investigations revealed that the epibiosis in the signal crayfish was determined by morphology of body surfaces. No epibionts were found on smooth surfaces with regular single setae (a known design that prevents fouling in aquatic environments). The dimpled surfaces with regular single micro-papillae may be considered as a newly described example of self-cleaning surfaces. Bio-inspired surface patterning presents promising approaches to the design of novel functional surfaces that can prevent biofouling. The new self-cleaning design may be used in further technological applications.

Protecting Complex Biodiversity Systems: Ciliophora Endosymbionts of the Threatened Freshwater Mussel Species Unio crassus

“…on the Ephemera danica Muller 1764, (Ephemeroptera: Ephemeridae) sampled in two small lowland rivers in Poland [35]. In other Polish river Ciliophora belonging Epistylididae (Sessilida) epibiotic ciliates were reported on the signal crayfish Pacifastacus leniusculus [36]. But role one of the ciliate taxon, Tokophrya sp., especially needs to explain, because three species of the genus were found in pathologically changed gills of the Red Swamp Crayfish Procambarus clarkii [37].…”