Epibiontic communities on the freshwater shrimpCaridina ensifera(Crustacea, Decapoda, Atyidae) from Lake Poso (Sulawesi, Indonesia)

Abstract

The epibiont communities of the freshwater shrimp Caridina ensifera, endemic to Lake Poso (Sulawesi, Indonesia), were analysed for the first time based on their morphological and biometrical characteristics and taxonomic position. Seven ciliated protozoans and a rotifer were examined: three suctorian ciliate protozoan species (Acineta sulawesiensis, Podophrya maupasi, and Spelaeophrya polypoides), three peritrichs (Zoothamnium intermedium, Vorticella globosa, and Cothurnia compressa), a haptorid (Amphileptus fusidens), and the rotifer species Embata laticeps. A mean number of 314.6 epibionts was found per shrimp specimen. The distribution of the epibiont species on the surface of the basibiont was recorded, to allow calculation of the density on the different colonized individuals of C. ensifera and on each anatomical unit of the shrimp. The most abundant species, Zoothamnium intermedium and Acineta sulawesiensis, were also the ones most widely distributed. The statistical analysis showed that Zoothamnium, Acineta, Podophrya, and Embata were the epibiont genera most widely distributed on the basibiont, and the pairs of epibiont genera Zoothamnium-Embata, Podophrya-Acineta, Spelaeophrya-Amphileptus, and Cothurnia-Vorticella followed a similar pattern of distribution. There was a significant difference between the distribution patterns of the different epibiont species on the shrimp. The analysis of the densities of the epibionts throughout the longitudinal axis of the shrimp showed a gradient from the anterior to the posterior end of the body, and a significantly different distribution of each epibiont species. Their colonization follows a certain pattern of behaviour, the species occupying the available substratum, with particular requirements of each functional group, but with a trend resulting in equilibrium among species and groups, compensating for diversity and density. The possible adaptations of the epibionts, as well as the colonization patterns are discussed.

4. Rotifera

“…Epiphanes daphnicola is feeding on the sessile unicellular euglenaceans (e.g., Colacium vesiculosum) and ciliates living on the carapace of their host (Matveeva 1989). Data on rotiferan epibionts of freshwater shrimp are restricted to Embata laticeps, which was the only and rather common rotifer on Caridina ensifera (Fernandez-Leborans & von Rintelen 2007). Their association with Asellus varies from very strict (Rotaria spp.)…”

Genetic analysis of ciliates living on the groundwater amphipod Crangonyx islandicus (Amphipoda: Crangonyctidae)

“…Due to low frequency of these species on our amphipods, we may have not detected them with our molecular method. In an ongoing study on the groundwater ecosystem, applying eDNA methods including sequencing of samples from the amphipods, we have observed the existence of two peritrich species, one of the genus Trichodina and one unspecific due to low match with available sequences (R. Gudmundsdottir, B. K. Kristjánsson, V. T. Marteinsson, S. Pálsson, in prep Only few epibiont taxa were found on the Icelandic groundwater amphipods and fewer observed than in several studies, where whole communities have been reported, for example on freshwater shrimp (Fernandez-Leborans & Von Rintelen, 2007), isopods in the deep sea (Ólafsdóttir & Svavarsson, 2002) and freshwater cladocerans (Threkeld & Willey, 1993). This might indicate an isolated habitat and an oligotrophic environment, which is consistent with the common description of subterranean, and cave, ecosystems as systems of food shortage (e.g., Fernandes, Batalha, & Bichuette, 2016), that might also apply to groundwater systems in the lava fields in Iceland.…”

“…A broad diversity of epibiotic organisms, ranging from prokaryotes to protists and multicellular eukaryotes (Fernandez-Leborans & Gabilondo, 2008;Fernandez-Leborans & Von Rintelen, 2007) live on the external surfaces of crustaceans (Fernandez-Leborans, 2010), including amphipods (Chantangsi et al, 2013), krill (Fernandez-Leborans, 2013), shrimp (Fernandez-Leborans, Zitzler, & Gabilondo, 2006) and crayfish (Mayén-Estrada & Aladro-Lubel, 2000), both in freshwater and the marine environment. The species composition and community structure of the epibionts can give information on the ecology of the host (Fernandez-Leborans, 2010) and about their interaction with the host, whether it represents symbiosis, commensalism or parasitism (Fernandez-Leborans, 2013).…”

Association of the alga Cladogonium sp. with a multifactorial disease outbreak in dwarf shrimp (Neocaridina davidi)

“…A number of relevant parasites affect N. davidi, and several organisms have been described to colonize the body surfaces of the shrimp. For example, various epibionts, including rotifers, nematodes, ciliates and others, can be found on freshwater shrimp, as these organisms normally populate the same habitats and benefit from a cooperative lifestyle (Corliss 1979, Fernandez-Leborans et al 2006, Fernandez-Leborans & Von Rintelen 2007, Maciaszek et al 2018. Fungi, fungallike organisms and bacteria may colonize the shrimp carapace as epibionts and, because many species are opportunists, they can sometimes cause infections as secondary pathogens (Gozlan et al 2014).…”