Parasites (Isopoda: Epicaridea and Nematoda) from ghost and mud shrimp (Decapoda: Axiidea and Gebiidea) with descriptions of a new genus and a new species of bopyrid isopod and clarification of Pseudione Kossmann, 1881

Abstract

Ghost and mud shrimps in Axiidea and Gebiidea are hosts to parasitic epicaridean isopods, including species in Bopyridae and Ionidae. These isopods can reach high prevalence levels on their mud shrimp hosts and may strongly influence host ecology and biology. Currently, 54 species of bopyrids and eight species of ionids are known to parasitize ghost and mud shrimps. We present new taxonomic data on three species of ionids and ten species of bopyrids (nine previously described and one new to science), as well as on an undescribed species of nematode from an axiidean host. New locality and host records are given for all species. Our analysis of new material and review of museum specimens includes the description of the new species Acrobelione halimedae n. sp. from Austinogebia spinfrons (Haswell, 1881). We also provide an improved definition for the genus Pseudione Kossmann, 1881, based on morphological characters found in both sexes, and resolution of the type species, P. callianassae Kossmann, 1881. In our revision of Pseudione we erect a new genus, Robinione, and placed two species therein: R. overstreeti (Adkison Heard, 1995) and R. brattstroemi (Stuardo, Vega Cespedes, 1986). In addition, two other species are removed from Pseudione: P. compressa (Shiino, 1964) is moved to Ionella Bonnier, 1900, and P. panopei Pearse, 1947 is considered a synonym of Progebiophilus upogebiae (Hay, 1917). Bopyrid isopods represent a large, diverse taxon and our findings help clarify the taxonomy of those species found on ghost and mud shrimps.

Review and guide to the isopods (Crustacea, Isopoda) of littoral and sublittoral marine habitats in the Southern California Bight

“…Female body length to ~ 12 mm (male ~ 3.9 mm). See Salazar-Vallejo and Leija-Tristán (1990) , Campos and de Campos (1998) , Espinosa-Pérez and Hendrickx (2001a , 2006 ), Markham (2005) , Boyko et al (2017) , and Aguilar-Perera (2022) .…”

“…Within the infraorder Epicaridea , the family Bopyridae has been treated in detail in a long series of papers by Markham since the 1970s (e.g., Markham 1974a , 1975 , 1977a , 1985a , 1986 , 1992 , 2001 , 2003 , 2004 , 2008 , 2016 , 2020 ), while Boyko and Williams (2021a , 2021b ) recently covered the two known local genera of the family Dajidae . Other valuable recent references for bopyrid and dajid isopods include Boyko et al (2017) , Williams et al (2019) , and Williams and Boyko (2021) .…”

Crustaceans as hosts of parasites throughout the Phanerozoic

“…Data in systematic studies on epicarideans echo variability in host specificity: An et al (2009: table 1) showed that most Progebiophilus spp. were restricted to one thalassinidean host species and both An et al (2015) and Boyko et al (2017) noted epicaridean species infecting only a single host species, whereas other epicaridean species were found on multiple, often related host species. For carid shrimp from Florida, each bopyrid species was found only on one host genus (Briggs et al 2017).…”

Topotype-based DNA Barcode of the Parasitic Isopod <i>Pseudione nephropsi</i> (Bopyridae), with a Supplementary Morphological Description

“…The genus Pseudione Kossmann, 1881 in the isopod family Bopyridae Rafinesque, 1815 presently comprises 47 species (Boyko et al 2008 onwards), all of which live as parasites in the gill chamber of astacidean, axiidean, gebiidean, anomuran, or caridean decapods (Boyko et al 2017). While these isopods show relatively few morphological modifications related to their parasitic mode of life (Williams and Boyko 2012), male and female Pseudione appear simpler in morphology than free-living taxa; for example, some appendages are lacking or reduced (e.g., uropods and pleopods in males), and there are fewer setae on the pereopods.…”