Accalathura schotteae, King, Rachael A., 2008

King, Rachael A., 2008, A re-description of Accalathura crenulata (Richardson, 1901) from type material and the description of two new Accalathura species (Crustacea: Isopoda: Cymothoida), Zootaxa 1761, pp. 17-29 : 24-27

Accalathura schotteae n. sp.

( Figs 4–5 )

Accalathura crenulata (in part).––– Menzies & Kruczynski, 1983: 35 –38, fig 12.

Material examined. HOLOTYPE, USNM 1111739, UMML 32.9263, Uva Reef, off Panama, 7°49'N, 81°46'W, 3 m, coll. P.W. Glynn, 7 March 2003, 1 ovigerous female (12 mm). PARATYPE, UMML 32.9264, Uva Reef, off Panama, 7°49'N, 81°46'W, 3 m, coll. P.W. Glynn, 9 March 2003, 1 mature male (8.5 mm). Other material. UMML 32.9260, Uva Reef, off Panama, 7°49'N, 81°46'W, 3 m, coll. P.W. Glynn, 7 March 2003, 4 immature specimens (11–13 mm). UMML 32.9261, Uva Reef, off Panama, 7°49'N, 81°46'W, 3 m, coll. P.W. Glynn, 7 March 2003, 1 immature specimen (10 mm). UMML 32.9265, Uva Reef, off Panama, 7°49'N, 81°46'W, 3 m, coll. P.W. Glynn, 15 September 2003, 1 immature specimen (13 mm). UMML 32.9267, Uva Reef, off Panama, 7°49'N, 81°46'W, 3 m, coll. P.W. Glynn, 8 March 2003, 2 immature females (13 m), 1 juvenile (10 mm). UMML 32.9268, Uva Reef, off Panama, 7°49'N, 81°46'W, 3 m, coll. P.W. Glynn, 9 March 2003, 1 juvenile (10 mm). UMML 32.9269, Uva Reef, off Panama, 7°49'N, 81°46'W, 3 m, coll. P.W. Glynn, 5 March 2003, non ovigerous female (13 mm). UMML 32.9270, Uva Reef, off Panama, 7°49'N, 81°46'W, 3 m, coll. P.W. Glynn, 15 September 2003, immature female (11 mm). UMML 32.9271, Uva Reef, off Panama, 7°49'N, 81°46'W, 3 m, coll. P.W. Glynn, 5 March 2003, immature female (10 mm). UMML 32.9272, Uva Reef, off Panama, 7°49'N, 81°46'W, 3 m, coll. P.W. Glynn, 10 March 2004, 1 juvenile (5 mm). USNM 1026798, off Crystal River, Florida, 28°24'N, 85°15'W, 175 m, 18 May 1974 – 30 Jun 1974, 1 female (22 mm). USNM 1026799, off Crystal River, Florida, 28°30'N, 83°21'W, 28 m, 18 May 1974 – 30 Jun 1974, 1 male (22 mm). USNM 225252, off North Carolina, 30°24'N, 76°34'W, 20 m, coll. Duke University, 19 May 1981, 1 immature female (10 mm). USNM 224002, off Fernandina Beach, Florida, 30°37'N, 81°10'W, 20 m, coll. Georgia Marine Resources For Minerals Management Service, 6 February 1980, 1 male (12 mm). USNM 1111740 (ex USNM 189044), Aruba, 10 April 1939, 1 immature female (12 mm).

Diagnosis. Antenna 1 shorter than antenna 2; antenna 1 flagellum more than 1.5 times as long as peduncle; antenna 2 flagellum distinctly longer than combined lengths of peduncular articles 3–5. Pereopod 1 propodus 2.4 times as long as broad (excluding ventral lobe). Pereopod 2 propodus 2.8 times as long as broad. Uropodal endopod narrow and tapered, 1.7 times as long as broad, with setae distributed laterally and distally. Telson broadest at mid-length, tapered to sub-acute point. Male pleopod 2 with appendix masculina apically bifid.

Description. Female. Head, pereon and pleon with distinct dorsal pigmentation. Clusters of long setae present laterally on pereon at articulations of pereopods.

Antenna 1 shorter than antenna 2. Antenna 1 peduncle with articles 2 and 3 similar length, flagellum longer than peduncle, with 19 articles. Antenna 2 peduncular article 3 shortest, article 4 and 5 similar length, flagellum similar length to peduncle, with 25 articles.

Mandibular palp second article with five long setae, third article with longitudinal row of 24 short robust setae and one long apical robust seta. Maxilla 1 slender and elongate with distal serration. Maxilliped palp with two articles, article 1 with two rows of long setae on inner edge, article 2 with seta at mid-length and 17 long terminal setae; endite not reaching past article 2 of palp, with subterminal long seta.

Pereopod 1 basis and ischium with rows of long dorsal setae; merus broader than long and enclosing carpus, with dorsal and ventral long setae; carpus ventral margin with a cluster of robust setulate setae and long setae; propodus 2.4 times as long as broad, with proximal ventral lobe, ventral margin between lobe and dactylus excavated, with long simple setae and short robust setulate setae along ventral margin and excavated section. Pereopod 2 basis and ischium with paired rows of long dorsal setae; merus as long as broad and enclosing carpus, with long dorsal and ventral setae; carpus with long ventral setae; propodus 2.8 times as long as broad, ventral margin with eight robust setae, six most proximal setae vary in lengths (fourth and fifth largest) and possess a setule at mid-length, the seventh and eighth most distal setae are bifid and trifid and lacking a setule at mid-length. Pereopod 3 basis and ischium with paired rows of long dorsal setae; merus longer than broad and covering carpus, with long dorsal and ventral setae; carpus with long ventral setae; propodus 3.2 times as long as broad, ventral margin with seven robust setae, five most proximal setae vary in lengths (middle setae largest) and possess setule at mid-length, sixth and seventh most distal setae are bifid and lacking setule at mid-length. Pereopods 4–7 becoming more elongate posteriorly, with short robust setae on carpus and propodus.

Pleopod 1 exopod 2 times as long as broad, with at least 50 distal long plumose setae; endopod shorter than exopod, 4.5 times as long as broad, with 10 distal long plumose setae. Pleopods 2–5 shorter than pleopod 1, exopod and endopod similar size, endopod with around 13 long plumose setae, exopod with around 18 long plumose setae.

Uropodal peduncle inner distal margin slightly raised, outer distal margin acute and distinctly raised, endopod distally rounded, 1.7 times as long as broad, with setae distributed laterally and distally. Uropodal exopod reaching past peduncle of endopod, dorsal and ventral margins with long plumose and simple setae (simple setae are concentrated apically). Telson broadest at mid-length, 2.6 times as long as broad, tapered to sub-acute point, with long simple setae distally, distal 1/3 margin with some slight serration between setae.

Male. (Sexually dimorphic characters) Antenna 1 flagellum with 23 articles, articles 2–12 with dense clusters of aesthetascs and setae. Antenna 2 peduncle similar to female, flagellum with 27 articles (slightly more than in female).

Pereopod 1 propodus in larger males (~ 22 mm) is more robust than in females, in smaller males (~ 12 mm) it is similar to the female, other pereopods as for female.

Pleopod 2 with appendix masculina apically bifid, length of appendix masculina (relative to the endopod and exopod rami) varies with size of adult male: in smaller males appendix masculina reaches past rami, in larger males of similar size to rami.

Distribution. Pacific Coast of Panama (type locality); Aruba; southeastern United States (Atlantic coasts of North Carolina, and Florida; Gulf coast of Florida).

Etymology. This species is named for Marilyn Schotte, of the National Museum of Natural History (Smithsonian), Washington D.C., who prompted this study by bringing the Panama material to the author’s attention.

Remarks. A. schotteae n. sp. is described from type material collected from the Pacific coast of Panama (USNM 1111739). During this study, additional specimens that were sometimes larger than the Panama specimens, but otherwise indistinguishable from the type material, were identified from the southeastern United States (USNM 225252, 224002; 10 mm immature female, 12 mm male) and the eastern Gulf of Mexico (USNM 1026798, 1026799; 22 mm female and male). Adult specimens of both sexes from Panama are consistently small (at ~ 9–12 mm), the Atlantic coast Florida and North Carolina specimens are 10–12 mm, and the Gulf of Mexico Florida specimens (male and female) are the largest (> 22 mm). Further sampling for this species within these areas and in the intermediate areas of the Caribbean, along with genetic evaluation of populations, should resolve the distribution of this species and the relationships among populations. The appendix masculina of males in the larger individuals (> 22 mm) was of a similar length to the pleopodal rami, which fits the pattern seen in A. kensleyi n. sp., where it appears that the pleopodal rami lengthen as the adult male grows, while the appendix masculina remains a constant length after its original development. The Atlantic and Gulf material did not show any clear body pigmentation (distinct in Panama specimens), but this could be due to long-term preservation in alcohol.

The apparent disjunctive nature of these populations is thought to be a reflection of the restricted scope of the examination as not all of the specimens labeled as A. crenulata in the NMNH collections could be examined. It is interesting that this species has a wide distribution from the Eastern United States and down to the Pacific, adjacent to the Panama Canal (and that A. crenulata is also recorded from the Atlantic coast of Panama in this study). It is likely that A. schotteae n. sp. species is distributed through the eastern United States, Gulf of Mexico and Caribbean, although it has remained cryptically intermixed within lots identified as A. crenulata .

Figures

FIGURE 4. Accalathura schotteae n. sp. USNM 1111739, holotype female, 12 mm. A, whole animal, dorsal view; B, pereopod 1; C, pereopod 2; D, maxilla; E, pereopod 3; F, distal end of pereopod 7; G, maxilliped; H, telson; I, uropodal exopod; J, mandible; K, uropodal endopod.

FIGURE 5. Accalathura schotteae n. sp. USNM 1111739, holotype female, 12 mm. A, pleopod 1; B, pleopod 2; UMML 32.9264, paratype male, 8.5 mm, C, pleopod 2 with appendix masculina.