Robinione overstreeti (Boyko & Williams & Shields, 2017)

Boyko, Christopher B., Williams, Jason D. & Shields, Jeffrey D., 2017, 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, Zootaxa 4365 (3), pp. 251-301 : 279-282

Robinione overstreeti ( Adkison & Heard, 1995) n. comb.

Figs 9 , 10

Pseudioniinae [sic] sp. A. Rakocinski et al., 1993: 102 (list).

Pseudione overstreeti Adkison & Heard, 1995 : 105 –109, figs. 1, 2 (type locality: west end of Horn Island, Mississippi, U.S. A, infesting Callichirus islagrande (Schmitt, 1935)) .— Rakocinski et al., 1996: 351 (list).— Camp, 1998: 134 (list).— Schotte et al., 2009: 980 (list).— Vogt, 2016: 1409, 1410 (mention), fig. 7A (color photo of male and female).

Material examined. United States: Immature female (5.5 mm), ex right branchial chamber of female Callichirus islagrande (10.9 mm CL), Gulf Beach, Isle Dernière, Louisiana, coll. R. B. Griffis & T. Zimmerman, 27 Jul 1993 (ULLZ 10206); immature female (5.5 mm, on SEM stub, USNM 1459847 ex ULLZ 10205), mature male (3.0 mm), ex right branchial chamber of female C. islagrande (8.0 mm CL), mid-intertidal pool and low intertidal, bay side, Isle Dernièrs, Louisiana, coll. R. B. Griffis, D. L. Felder & T. McTigue, 19 Oct 1993 (ULLZ 10205); ovigerous female (11.0 mm), mature male (4.0 mm), ex left branchial chamber of female C. islagrande (11.4 mm CL), Gulf side, Isle Dernièrs, Louisiana, coll. D. L. Felder, P. Klerks & D. Griffis, 22 Jan 1995 (ULLZ 10207); immature female (11.0 mm), mature male (4.0 mm), ex left branchial chamber of female C. islagrande (10.8 mm CL), Gulf side of beach, Isla Dernièrs, Louisiana, coll. R. B. Griffis & T. Zimmerman, 27 Jul 1993 (ULLZ 10199); female (11.0 mm), ex left branchial chamber female C. islagrande (10.1 mm CL), Gulf side of beach, Isle Dernièrs, Louisiana, coll. R. B. Griffis, D. L. Felder & T. McTigue, 19 Oct 1993 (ULLZ 10209); immature female (3.0 mm), ex left branchial chamber of immature C. islagrande (5.0 mm CL), immature female (3.7 mm), mature male (2.3 mm, on SEM stub, USNM 1459848 ex ULLZ 10198), ex left branchial chamber of immature C. islagrande (5.0 mm CL), immature female (3.5 mm), mature male (2.0 mm), ex right branchial chamber of female C. islagrande (6.5 mm CL), immature female (3.5 mm), mature male (2.2 mm, on SEM stub, USNM 145 9848 ex ULLZ 10198), ex right branchial chamber of female C. islagrande (5.0 mm CL), access road #3, near Fish Pass, low tide, morning, Mustang Island, Texas, coll. D. L. Felder & L. Bilodeau, 1 Mar 2000 (ULLZ 10198); ovigerous female (12.0 mm), mature male (4.5 mm), ex C. islagrande (host not in vial with parasites), Gulf side, Isle Dernièrs, Louisiana, coll. D. L. Felder & R. B. Griffis, 24 Jul 1992 (ULLZ 10210); ovigerous female (11.0 mm), mature male (4.5 mm), ex left branchial chamber of female C. santarosaensis Sakai and Türkay, 2012 (11.4 mm CL), bay side, Isle Dernièrs, Louisiana, coll. A. Christian, D. Badgwill, R. B. Griffis & I. A. Griffis, 22 Jan 1993 (ULLZ 10204).

Distribution. Gulf of Mexico from west coast of Florida to Texas, U.S.A., and Tabasco, Mexico.

Hosts. Callichirus islagrande (Schmitt, 1935) (type species) and C. santarosaensis Sakai & Türkay, 2012 .

Remarks. The present material of R. overstreeti n. comb. ( Figs. 9 , 10 ) matches that of Adkison & Heard (1995), who provided a detailed description of the species. Although they did not show the ventral view of the male, Adkison & Heard (1995) indicated that the pleopods were “vestigial or absent, represented by low mounds mesal to lateral processes of pleomeres” as we found in our samples ( Fig. 10D ). The male pleomeres documented in Adkison & Heard (1995; Fig. 2A ) are slightly more elongate and acute than in the present specimens, but this variation is typical for pleopodal morphology in bopyrids. Each male pereopod of R. overstreeti n. comb. has a recurved dactylus, the distal end of which touches the base of the propodus and is surrounded by a low ridge of tooth-like projections ( Fig. 10B, C ). The female R. overstreeti n. comb. examined with SEM ( Fig. 9 ) is not fully mature, thus has reduced oostegites and, proportionally, somewhat longer and thinner pleopods and uropods than the holotype ( Adkison & Heard, 1995; Fig. 1B ). Female and male antennae ( Figs. 9B , 10B ) have the same numbers of articles as in the original description (3 and 4 for females; 3 and 5 for males). Female R. overstreeti n. comb. have pereopods with elongate carpi and a large irregular, infolded mass on the dorsal surface of each of the bases ( Fig. 9C, D ), all pereopodal segments covered with scales ( Fig. 9C–F ).

Felder & Dworschak (2015) discussed in detail the nomenclatural issues surrounding the name C. santarosaensis , which is now used for Gulf of Mexico populations of the Callichirus species formerly called C. major (Say, 1818) , but which is distinct from that Atlantic coastal species. This is the first record of “ Pseudione ” overstreeti from C. santarosaensis (either under that name or as C. major ). Adkison & Heard (1995) examined several hundred C. santarosaensis (as C. major ) and found no bopyrids on them; it is not clear where their specimens were collected from, but based on the material examined list for P. overstreeti , they probably came from Alabama or Mississippi.

Figures

FIGURE 1. A–C, Ione thompsoni Richardson, 1904 (YPM IZ 089393) ex Gilvossius setimanus (DeKay, 1844)). A, dorsal overview of female; B, ventral overview of female with male in situ; C, ventral overview of male. D, photograph of live male Callianassa truncata Giard & Bonnier, 1890 (NHMW 20514) from Croatia bearing Ione thoracica (Montagu, 1808) (NHMW 25810) in left branchial chamber. Scale bars:A–C = 2 mm; D = 5 mm.D courtesyof Peter Dworschak.

FIGURE 2. Variation in pleopod morphology of Ione thoracica (Montagu, 1808). A, pleopod 1 of specimen identified by Bonnier (1900) as Ione vicina Bonnier, 1900 from Naples, Italy, note short endopod (arrow); B, pleopod 1 of specimen identified by Bonnier (1900) as I. thoracica from unspecified locality, but most likely Wimereux, France, note long endopod (arrow); C, pleopod 1 of specimen from Volosko, Croatia (NHMW 25807 ex Callianassa truncata Giard & Bonnier, 1890); D, pleopod 1 of specimen from Lido di Staranzano, Italy (NHMW 25231 ex Pestarella tyrrhena (Petagna, 1792)); E, pleopod 1 of specimenfrom Volosko, Croatia (NHMW 25810 ex C. truncata); F, pleopod 1 of specimen from Hammamet, Tunisia (NHMW 25809 ex C. truncata). A, B from Bourdon 1968; not to scale. Scale bars: C–F = 0.5 mm.

FIGURE 9. Scanning electron micrographs of Robinione overstreeti (Adkison & Heard, 1995), n. comb., mature female (ex Callichirus islagrande (Schmitt, 1935), ULLZ 10205). A, ventral overview of female; B, ventral view of head, left side, showing antennule (A1), antenna (A2), mouth (m), maxilliped palp (Mxp), and pereopod 1 (Pe); C, right pereopod 3, arrowhead indicates basis with dorsal mass; D, left pereopods 5–7 (left to right), arrowhead indicates basis with dorsalmass on pereopod 5; E, scales of basis of right pereopod 3; F, scales of carpus of right pereopod 3. Scale bars: A = 1 mm; B, C = 100 µm; D = 250 µm; E, F = 10 µm.

FIGURE 10. Scanning electron micrographs of Robinione overstreeti (Adkison & Heard, 1995), n. comb., mature male (ex Callichirus islagrande(Schmitt, 1935), ULLZ 10198).A, ventral overview of male; B, ventral view of head, left side, showing antennule, antenna, mouth, and pereopod 1; C, left pereopods 6 and 7 (top and bottom, respectively); D, ventral view of pleon, showing pleopodswith rounded medial lobes (noted on third and fourth pleopodsby asterisks).Scale bars: A = 500 µm; B, C = 100 µm; D= 200 µm.