First molecular identification of Vorticella sp. from freshwater shrimps in Tainan, Taiwan

Abstract

Freshwater shrimps are the most common crustaceans kept in an aquarium. This study was a survey seeking parasites infecting cultured freshwater atyid shrimps at aquarium stores in Tainan, Taiwan. We observed that atyid shrimps were infested with Vorticella and Scutariella. Scutariella is a common shrimp parasite; thus, we focused on Vorticella infection in the atyid shrimps. Vorticella aequilata-like pop TW, a freshwater peritrich ciliate, was isolated from the atyid shrimps. The morphological characteristics were investigated using live observations. Specimens from the population showed identical arrangement of the infraciliature and identical ITS1-5.8SITS2 region sequences. The zooids are bell-shaped, 40–58 μm wide and 47–70 μm in long in vivo. The food vacuole is variable in shape and is located in the middle of the cell. ITS1-5.8S-ITS2 sequences of Vorticella aequilata-like pop TW did not match any available sequences in GenBank. Phylogenetically, Vorticella aequilata-like pop TW clusters with the other Vorticella within the family Vorticellidae and nests with Vorticella aequilata in the subclade. Above all, the morphological characteristics and molecular analyses show that the investigated Vorticella is a Vorticella aequilata-like species. The phylogenetic analyses of ciliates based on the ITS1-5.8S-ITS2 sequences reveal that the Vorticella genus consists of Vorticella morphospecies and that taxonomic revision of the genus is needed. Morphometric criteria and molecular analysis were used to describe and identify the Vorticella specie and this study presents the first molecular identification analysis of the Vorticella species in the cultured atyid shrimps in Tainan, Taiwan.

Morphological and molecular identification of epibiontic sessilid Epistylis semiciculus n. sp. (ciliophora, Peritrichia) from Procambarus clarkia (Crustacea, Decapoda) in China

“…These findings further verified the deficiency of some morphological characteristics used in species identification, such as body size and granules (Jiang et al, 2016; Wang et al, 2017b). These results highlighted the importance of molecular data for sessilid identification and pathogenic diagnosis (Miao et al, 2004; MartínCereceda et al, 2007; Gentekaki et al, 2017; Liao et al, 2018). The present study acted as a case for precise identification of sessilids from Procambarus clarkia : more data, especially comprehensive molecular data, should be considered when morphological identifying getting into dilemma.…”

“…Sessilids have repeatedly been reported adhering to edible crustacean during the late-20th century, causing potential damage to host health (López-Téllez et al, 2009). Many sessilids species were detected adhereing to crustacean in China, American, and Mexico, such as Zoothamunium , Vorticella and Epistylis (Hunn, 1966; Song et al, 1991; Hongwei and Overstreet, 2006; Liao et al, 2018). In the present study, we detected sessilids adhering onto intermolt period Procambarus clarkia tissues.…”

First report of Scutariella japonica (Matjašič, 1990), a temnocephalid epibiont from South-East Asia, found on introduced ornamental freshwater shrimp in European waters

“…These locations belong to suitable for S. japonica, thanks to water moves regularly delivering organic matter (Maciaszek et al, 2018). Similar location preferences can be observed in vorticellids, however, their colonies are found also in other body parts (Patoka et al, 2016a;Liao et al, 2018;Maciaszek et al, 2018). Scutariella japonica is known to spend most of its life in host gills where is lays eggs (Matja sič, 1990).…”

“…It may suggest that the habitat conditions of Ciepły Canal are not proper for the species, although vorticellids quantity implies optimal levels of organic matter in the water (Maciaszek et al, 2018). On the other hand, it could be an effect of increased predation on shrimp infected by this epibiont due to possible host stress (Liao et al, 2018;Maciaszek et al, 2018). In most cases S. japonica adults or eggs were observed at once with melanized damages in host gills, except two hosts in which only adults were found, possibly recently invaded.…”

“…Mass quantities of S. japonica specimens (as well as vorticellids) can be dangerous especially for moulting crustaceans. Shrimp may not survive this process due to stress caused by the activity of the epibiont as well as host weakness can be used as a potential gate for infections of other organisms (Liao et al, 2018;Maciaszek et al, 2018).…”