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.