An invaded invader: high prevalence of entocytherid ostracods on the red swamp crayfish Procambarus clarkii (Girard, 1852) in the Eastern Iberian Peninsula

Abstract

The American red swamp crayfish Procambarus clarkii (Girard, 1852) was introduced in 1973 into the Iberian Peninsula for commercial purposes. As a result of both the expansion from the Iberian Peninsula and, probably, further introductions in other European countries, now it is widely distributed throughout much of Europe. The ecological impacts of this invading crayfish have received increasing attention, but nothing is known about its symbiotic entocytherid ostracods outside the American continent. The present survey has examined more than 200 crayfishes from 12 localities distributed over a wide area of Eastern Spain. Entocytherid ostracods were extracted from individual crayfishes and they were identified, counted, assigned to developmental instars and sexed. In all the study locations but one, we found at least one crayfish individual infected by entocytherid ostracods and the species determined was the same in all cases: Ankylocythere sinuosa (Rioja, 1942). The number of ostracods on individual P. clarkii varied notably in relation to crayfish size and also differed significantly among sampling sites. The crayfish size effects on ostracod densities might be related to the amount of resources and to the crayfish age and moulting frequency affecting ostracod distribution and population structure. In addition, the spatial variation in ostracod densities could also be related to site-specific habitat traits and the variability of crayfish population dynamics. Our study represents the first citation of an alien entocytherid species in Europe and demonstrates its wide distribution in the Iberian Peninsula. Further research is needed to know the potential effects of this ostracod species on the ecology of P. clarkii and of native species, with implications on the management of this aquatic invader.

Dynamics of Ostracoda (Crustacea) assemblages in a Mediterranean pond system (Racó de l'Olla, Albufera Nat. Park) with focus on the exotic speciesCandonocypris novaezelandiae(Baird, 1843)

“…This idea is corroborated with the presence of two alien species in our study; not only C. novaezelandiae but also F. subacuta (see Escriva`et al, 2012). However, it should be noted that these ostracods might have been introduced not only by birds, but also by human activities, wind or other animals (Fox, 1965;Serramo et al, 1999;Vanschoenwinkel et al, 2007Vanschoenwinkel et al, , 2008Waterkeyn et al, 2010;Sabagh et al, 2011;Aguilar-Alberola et al, 2012). Taking into account these new questions arising from our work, we suggest Table 1. for future studies to increase sampling efforts on aquatic habitats of the Iberian Peninsula with high density of migratory birds and/or intense human activities, so as to carry out genetic studies of the different populations of C. novaezelandiae to decipher its biogeographic history, trying to detect the mechanisms and factors that have facilitated its spreading and last, but not least, find out whether or not such small organisms as alien ostracods have notable ecological effects in the colonized aquatic ecosystems.…”

Long-anticipated new records of an ectosymbiotic branchiobdellidan and an ostracod on the North American red swamp crayfish, <i>Procambarus clarkii</i> (Girard, 1852) from an urban stream in Tokyo, Japan

“…Entocytherids were dissected in glycerol, mounted on microscope slides and identified using Hart & Hart (1974) and Aguilar-Alberola et al (2012). One mounted specimen of a branchiobdellidan and that of a copulat- ing couple of entocytherid have been deposited in the Invertebrate Collection of the Hokkaido University Museum, Sapporo, Japan (ICHUM 5337 and 5338).…”

“…Among the branchiobdellidans, Cambarincola mesochoreus Hoffman, 1963 was found in northern Italy (Gelder et al 1994(Gelder et al , 1999 and southwest France (J-F Parpet unpublished data), whereas this species and Cambarincola pamelae Holt, 1984 were observed to have relocated onto the blue crab, Callinectes sapidus Rathbun,1896, in the Chesapeake Bay, Maryland, USA (Gelder & Messick 2006). Reports of transported entocytherids are also sparse, and limited to two species in Spain, France, Germany, the Netherlands, the UK, the Czech Republic, and Japan (Smith & Kamiya 2001;Aguilar-Alberola et al 2012;Mestre et al 2013;Huys et al 2014).…”

Transmission and terrestrial dispersal of non-native ectosymbionts on invasive crayfish

“…In Europe, invasion of North American crayfish has been aided by their ability to transmit crayfish plague (Aphanomyces astaci Schikora, 1906), which has caused high mortalities of susceptible native crayfish species (Holdich et al, 2014;Svoboda et al, 2016). Whilst A. astaci is arguably the most detrimental introduced crayfish symbiont, various crayfish ectosymbionts including branchiobdellidans, temnocephalans and ostracods have also been co-introduced globally Ohtaka et al, 2005;Aguilar-Alberola et al, 2012;du Preez & Smit, 2013). These introductions have almost certainly been instigated by anthropogenic activity.…”