Gilvossius setimanus ( De Kay, 1844 )

Gilvossius setimanus ( De Kay, 1844) View in CoL

( Figs. 1 View Figure 1 , 6 A–C View Figure 6 )

Gonodactylus setimanus De Kay, 1844: 34 , pl. 8, fig. 23.

Callianassa stimpsoni Smith View in CoL , in Verrill, Smith and Harger, 1873: 549, pl. 2, fig. 8.

Callianassa stimpsoni View in CoL .– Kingsley, 1878: 327 (appendix page 12); Kingsley, 1879: 410; Kingsley, 1899: 823 (text fig. 6), 824 (key); Borradaile, 1903: 548; Rathbun, 1905: 17; Fowler, 1912: 570–571; Sumner et al., 1913: 141; Hay and Shore, 1918, 406, pl. 28, fig. 5; Fish, 1925: 159.

Callianassa atlantica Rathbun, 1926: 107 View in CoL .

Callianassa atlantica View in CoL .– Rathbun, 1935: 104; Schmitt, 1935: 4; Williams, 1965: 100 (key), 101, 102 (part, not Franklin County, Florida), fig.79; Biffar, 1970: 48, tab. 2; Biffar, 1971a: 639–641, 652–654 (key), 671, 694; Biffar, 1971b: 229; Williams, 1974: 16 (key), 41 (part, not Franklin County, Florida), fig. 43A, B; Rabalais et al., 1981: 101 (part, not Gulf of Mexico), fig. 2b, c, e, f, h; Williams, 1984: xiii, 180, 181 (part, not Franklin County, Florida), fig. 125a–d; Abele and Kim, 1986: 26 (part, not Franklin County, Florida), 294 (key), 297, 300 (legends a, b, c), 301 (figs. a, b, c); Manning and Felder, 1991: 765.

Callianassa (Callichirus) atlantica View in CoL . – de Man, 1928a: 37, pl. 9, fig. 17–17d; de Man, 1928b: 28, 94, 112; Williams, 1965: 102, fig. 79.

Callichirus atlantica .– Gurney, 1944: 89.

Callianassa setimanus View in CoL .– Manning, 1987: 386–388 (part, not Gulf of Mexico).

Gilvossius setimanus View in CoL .– Manning and Felder, 1992: 558–560 (part, not Miami and Gulf of Mexico), fig. 1a–g; Tudge et al., 2000: 133–134, 136, 143, 147, figs 3, 4; Heard et al., 2007: 16 (key), 21–22 (part, not Gulf of Mexico), fig. 24; Felder et al., 2009: 1062, 1093 (part, not Gulf of Mexico and Colombia); Sakai, 2005: 47–48 (part, not Gulf of Mexico and Colombia); Sakai, 2011: 372–373, 374 (key), 378–379 (part, not Gulf of Mexico and Colombia); Dworschak et al., 2012: 177, 192.

Callianassa setimana . – Sakai, 1999: 29 (part, not Gulf of Mexico and Colombia).

Materials examined. Atlantic coast U.S.A. (type not extant). Florida: 1 immature female, pocl 7.2 mm ( USNM 1549424 About USNM = ULLZ 16231 View Materials ), Fort Pierce Inlet , Dynamite Point, intertidal sand flat, 27°28.40’N 80°17.79’W, 27 July 2005 GoogleMaps . North Carolina: 1 female, pocl 7.8 mm ( USNM 51007 About USNM ), just outside Beaufort Harbor, R / V Fish Hawk, dredge, 23 m depth, 34°37’N 76°95’W, 7 September 1913 . Rhode Island: 1 female (photograph voucher), pocl 12.5 mm ( USNM 20869 About USNM ), Newport shoreline, 1880 . Connecticut: 1 mutilated female (DNA voucher), carapace missing ( YPM IZ 067307 ) , Long Island Sound, Thimble Islands , muddy sand, 0–0.5 m depth, 41°14.61’N 72°45.53’W, 14 August 2013 GoogleMaps . Massachusetts: 1 female, pocl 9.2 mm ( USNM 12902 About USNM ), Buzzards Bay , Naushon Island, 19 September 1887 ; 1 male, pocl 28.5 mm ( USNM 14096 About USNM ), Martha’s Vineyard, R / V “Fish Hawk”, dredge, 7–18 m depth, 6 September 1883 ; 1 male (photograph voucher), pocl 13.9 mm, 1 female (photograph voucher), pocl 15.5 mm ( USNM 9238 About USNM ), Woods Hole, 19 November 1884 .

Morphological diagnosis. Antennular peduncle third (distal) article 4–5 times length of second (penultimate) article (sometimes shorter in juveniles). Adult eyestalks terminated distally in distinctly divergent elongate spines. Second maxilliped exopod equal to length of endopod merus, endopod with propodus length more than three times propodus width. Third maxilliped with operculiform ischium-merus subrectangular in outline, width of ischium less than length. Adult male major chela fixed finger opposable margin with primary tooth positioned at or proximal to midlength, distal slope of tooth commonly forming abrupt marginal offset or abutting small notch, opposable margin serrate (coarsely granulate or denticulate)proximal to primary tooth (primary tooth sometimes no larger than others near midlength of finger,especially in females).Third pereopod propodus with distoventral margin cuspate, marginal setation separated into distinct clusters. Telson rounded over posterior half, posterior margin with small median spine (sometimes as minute vestige).

Diagnostic gene sequence. GenBank accession number for YPM IZ 067307: (16S) MN 726521.

Habitat. The confirmed depth range remains as stated by Williams (1984), who reported the species from intertidal shores to subtidal waters of about 38 m depth. The much greater offshore depths reported by Manning (1987: 386) and Felder et al. (2009: 1062) were based on northwestern Gulf of Mexico populations (sensu Rabalais et al., 1981) that are no longer assignable to this species. Habitats include muddy sands of beaches, intertidal to shallow subtidal shoals and sand bars, embayments, and nearshore bottoms of open waters.

Distribution. Bass River Nova Scotia, south along U.S. Atlantic seaboard to vicinity of Fort Pierce Inlet, Florida.

Remarks. Manning (1987) reviewed history pertaining to the mutilated type of this species, which was originally reported as a new species of stomatopod taken from the stomach of a commercial cod in a New York fish market. While the fragmentary type specimen is no longer extant, other intact materials taken from near the type locality are now accepted to represent the species. Williams (1984: 181) reviewed a number of additional references that almost certainly apply to reproductive periodicity and larval life history of this species, though some, like that of Frankenberg and Leiper (1977), are now known to instead represent Biffarius biformis ( Biffar, 1971b) (see Rabalais et al., 1981: 112). The distributional range reported by Williams (1984: 181), and repeated by Abele and Kim (1986: 26) extended to the coast of Franklin County in the panhandle of Florida, bordering the northeastern Gulf of Mexico. However, no specimens have been located in the USNM or elsewhere to suggest that this record might indeed represent G. setimanus s.s., and that report is deemed to more likely represent one of the new species in the accounts that follow.

The history of generic reassignments of this species and its congeners by Sakai (1999; 2005; 2011) was reviewed by Poore et al. (2019), who rediagnosed and clarified membership of the genus, drawing upon morphological and molecular phylogenetic analyses by Robles et al. (2020). The report of Callianassa setimana from Caribbean waters of Colombia by Sakai (1999: 29) is not for the present included in the distributional range of G. setimanus s.s. Reported without supporting illustrations or comparative analyses, that identification was apparently based solely on juvenile specimens taken from a tropical locality that is widely disjunct from confirmed populations of this species.

The Miocene and Pleistocene fossils reported as Callianassa atlantica Rathbun, 1926 s.l. by Rathbun (1935) are not here included in the synonymy for G. setimanus ,thoughatleastsomecouldrepresenthistorical populations of the species. While those specimens originated from sites in Maryland, Virginia, and North Carolina that fall within the modern coastal range of the species, subtle morphological distinctions now used to separate G. setimanus s.s. from its congeners cannot be readily applied to fragmentary fossil materials.