The name of a model species: the case of Orchestia cavimana (Crustacea: Amhipoda: Talitridae)

Abstract The species commonly known as Orchestia cavimana belonging to the Talitridae family (Amphipoda) has been used as crustacean model species. Here, we point out that this talitrid amphipod species is related to species in the genus Orchestia but now falls under what is described as Cryptorchestia garbinii, which is a different species from the nominal species Cryptorchestia cavimana endemic to the Island of Cyprus. It is therefore important that future basic research and applied studies involving this model organism refer to it as C. garbinii. Its old assignment O. cavimana, or even C. cavimana, as still reported in the National Center for Biotechnology Information (NCBI) GenBank and in recent papers, may lead to confusion.

In recent years, basic studies have highlighted the utility of model species to perform a variety of research experiments, translating into significant contributions to theoretical and practical aspects (Liu et al. 2017;Sanz et al. 2017). Particularly noteworthy are certain amphipod species (Crustacea) that have become model organisms for biological investigations conducted in the laboratory setting. They are used in both fundamental research (e.g. in developmental genetics, Stamataki & Pavlopoulos 2016), and applied studies such as those for toxicology and genotoxicology assessment purposes (Davolos et al. 2015;Ronci et al. 2015Ronci et al. , 2017Di Donato et al. 2016). Indeed, these crustacean amphipods are both easy to keep in culture and easy to breed in a laboratory environment. They have a short generation time and produce embryos with salient features that have been well investigated (Hunnekuhl & Wolff 2012;Stamataki & Pavlopoulos 2016). Moreover, the relevance of these model organisms to the evolutionary tree is shown by several phylogenetic results as well as by the peculiarity of their genomes and mitogenomese.g. the occurrence of particular gene rearrangements (Davolos & Maclean 2005;Ito et al. 2010;Krebes & Bastrop 2012;Stokkan et al. 2016).
Orchestia cavimana belonging to the Talitridae family (Amphipoda) has been used as a crustacean model species both in cellular differentiation studies at the molecular level, and in the spatiotemporal expression of genes (Luquet et al. 1996;Gerberding & Scholtz 2001;Raz et al. 2002;Testenière et al. 2002;Wolff & Scholtz 2002, 2008Hecker et al. 2003Hecker et al. , 2004Ungerer et al. 2011;Hunnekuhl & Wolff 2012). However, it is highly important for the scientific community to keep updated with the most recent taxonomic position of model species. Orchestia cavimana has not only been transferred to the recently described new genus Cryptorchestia (Lowry & Fanini 2013), but as a result of genetic evidence (Ketmaier & De Matthaeis 2010), followed by a taxonomic revision (Ruffo et al. 2014), the current accepted name for the species is Cryptorchestia garbinii. This new taxonomic position differentiates the species from the nominal species Cryptorchestia cavimana (Ruffo et al. 2014 Ruffo et al. 2014). So although it might still be consistent with past and previous literature (see above), the species must not be referred to any more as O. cavimana.
In addition, our recent molecular and taxonomic analyses helped to clarify the evolutionary history of C. garbinii and the currently described In conclusion, being a model species for research has both costs and benefits. A wider notoriety in the scientific community as a model species includes appropriate taxonomic and molecular analyses to evaluate the extent of phenotypic and species-level genetic variation, such as to identify also cryptic species (Major et al. 2013;Fišer et al. 2018). It is therefore important and necessary that future basic research and applied studies involving this species refer to it as C. garbinii. Its old assignment O. cavimana, or even C. cavimana, as still reported in the National Center for Biotechnology Information (NCBI) GenBank (e.g. GenBank accession number AY744907.1) and in recent papers (e.g. Ramm & Scholtz 2017), may lead to confusion and misjudgement.

Acknowledgements
Two reviewers examined critically the manuscript. Their insightful comments led to an improvement of the note.

Disclosure statement
No potential conflict of interest was reported by the authors.