Alpheus hephaestus, Bracken-Grissom, Heather D. & Felder, Darryl L., 2014

Bracken-Grissom, Heather D. & Felder, Darryl L., 2014, Provisional revision of American snapping shrimp allied to Alpheus floridanus Kingsley, 1878 (Crustacea: Decapoda: Alpheidae) with notes on A. floridanus africanus, Zootaxa 3895 (4), pp. 451-491 : 470-474

Alpheus hephaestus sp. nov.

( Figures 2 g–i, 12a–g, 13a–f, 14a–g)

Alpheus floridanus— Wicksten 1983: 45; Kim & Abele 1988: 53, fig. 22 a–m (part, Mexico, Panama, Ecuador); Vargas 1999: 901; Wicksten & Hendrickx 2003: 64; McClure 2005: 141 (part, fig. 22 a–m only, from Kim & Abele 1988); Hendrickx 2005: 165.

Alpheus floridanus A (E. Pac.)— Williams et al. 2001: 377.

Type material. Costa Rica (Pacific coast). Holotype: male, cl 8.8 mm ( USNM 1265093 = tissue/sequence ULLZ 6205), west of Loma, 0 9°24.03’N, 84°29.20’W, stn. 48, R/V Urraca, trawl, 44.5– 42.5 m, 17 July 2005, H. Bracken, R. Collin et al. Paratypes: 1 ovig. female, cl 6.6 mm ( ULLZ 6377), same collection data as for holotype; 1 male, cl 9.1 mm ( ULLZ 6204), Bahía Naranjo, 10°44.04’N, 85°41.37’W, stn. 13, R/V Urraca, dredge, 40.2 m, 15 July 2005, H. Bracken, R. Collin et al.

Additional material. Costa Rica (Pacific coast): 2 males ( ULLZ 8004), 1 male, 3 ovig. females ( ULLZ 9507), 0 9°24.03’N, 84°29.20’W, stn. 48, R/V Urraca, trawl, 44.5– 42.5 m, 17 July 2005, H. Bracken, R. Collin et al.; 1 ovig. female ( ULLZ 6206), 10°47.29’N, 85°43.58’W, stn, 19, R/V Urraca, dredge, 39.5 m, 15 July 2005, H. Bracken, R. Collin et al.; 1 male ( ULLZ 6375), 0 9°24.03’N, 84°29.20’W, stn 48, R/V Urraca, dredge, 44.5– 42.5 m, 17 July 2005, H. Bracken, R. Collin et al. Panama (Pacific coast): 1 male, 2 females (1 ovig.) ( USNM 237984), 1 ovig. female, ( USNM 237984), Venado Beach Spit, stn. 132–2; 2 females (1 ovig.) ( USNM 237988), East of Panama Canal Channel, stn. 150-C, 19 April 1973; 2 males ( USNM 237987), Amador Causeway, Isla Naos, stn. 141–B; 3 male, 5 females (3 ovig.) ( ULLZ 9508), 0 7°41.70’N, 81°42.50’W, stn 1, R/V Urraca, dredge, 100 m, 21 February 2007, D. Felder et al.; 1 ovig. female ( ULLZ 9509), 0722.47’N, 80°16.19’W, stn 1, R/V Urraca, dredge, 20–25 m, 22 February 2007, D. Felder et al. Ecuador: 2 males, 1 female ( USNM 237981), Cape San Francisco, stn. 216–34, 20 fathoms (= 36.5 m), 11 February 1934; 1 male ( USNM 237990), Cape San Francisco, stn. 850–38, 23 February 1938. Mexico (Pacific coast): 1 male ( USNM 237989), Baja California, Agua Verde Bay, stn. 655–37, 10 fathoms (= 18.2 m), 10 March 1937; 2 males, 1 female ( USNM 237983), Baja California, Gonzaga Bay, Willards Point, stn. 714–37, 16–30 fathoms (= 29.2–54.8 m), 23 March 1937.

Description (based on holotype unless otherwise indicated). Carapace with narrow, acute rostrum, not exceeding first article of antennular peduncle, shallow median postrostral carina extending onto midlength of carapace, flanked anteriorly by adrostral furrows reaching posteriorly to base of eyes, shallow carapacial grooves extending posteriorly from pterygostomial angle and postorbital hood (not in all material examined) ( Fig 12 a, b, c); ocular hoods ovate to subtriangular, extending beyond eye, unarmed; anterolateral margin of carapace weakly concave adjacent to orbital hoods; pterygostomial angle distinct, angle acutely produced toward anterior; cardiac notch deep.

Antennular peduncle first article with large ventromesial carina ending in acute tooth, first article about 3.5 times length of width, second article about 4.2 length of width, third article about 1.5 length of width ( Fig. 12 a, b, c); mesial flagellum narrower than lateral, distal ½ of lateral bearing aesthetascs; stylocerite broad, lamellate, tapering into sharp tip, not over-reaching distal margin of first article. Antenna with stout basicerite bearing strong, sharp, ventrolateral tooth; antennal scale (scaphocerite) broad, lateral margin weakly concave to almost straight, distolateral spine barely over-reaching rounded anterior margin of blade and length of third article, not exceeding carpocerite (12a, c).

Mandible incisor process (right and left) with five or six well-developed teeth, one enlarged, on inferior half of margin ( Fig. 13 a), dentition of superior half poorly defined; molar process rounded, blunt; palp two-segmented palp. Maxillule, maxilla, first and second maxilliped typical for genus (13b–e). Third maxilliped exopod slender, setose, not extending beyond antepenultimate article of endopod ( Fig. 13 f); endopod terminal article flattened, spatulate, densely covered in thick setae, penultimate article subrectangular, broadening distally, bearing fringe of long setae extending from ventrodistal lip, antepenultimate article quadrate, sparsely setose.

First pereopods (chelipeds) unequal in size and shape ( Figs. 12 a, d, e; 14 a, b); major cheliped ischium short; merus subrectangular, ventral surface flattened, four movable spines and fringe of setae along ventromesial margin; carpus cup-shaped, small subacute tooth protruding from ventromesial margin; major chela subrectangular, laterally compressed, elongate, lacking depressions or grooves, margins sparsely setose, chela length about 4 times height; propodus length about 2.8 times dactylus length, ventral surface densely setose, mesial and lateral surface of palm smooth; dactylus setose, truncate distally. Minor cheliped ischium short; merus subrectangular, ventral surface flattened, with possibly four movable spines along ventromesial margin, but some appear broken/damaged (eight in male paratype, ULLZ 6204); carpus stout, cup-shaped; chela slender, long, lacking depressions or grooves, chela length about 5.5 times height, palm smooth, about 1.7 as long as dactylus, linea impressa evident, fingers densely setose.

Second pereopod slender ( Fig. 14 c), ischium slightly longer than merus; carpus composed of five articles with length ratio about 1:1:1:2.6:2 (distal to proximal); chela simple, fingers slightly longer than palm, sparsely setose distally. Third pereopod robust ( Fig. 14 d), ischium armed with movable spine on ventrolateral surface; merus about twice as long as carpus length; propodus slightly longer than carpus, four movable spines along ventrolateral margin, thick setae along entire superior and ventral margins and fringe along distal superior and ventral margin; dactylus simple, subspatulate, curved. Fourth pereopod similar to third, shorter, more slender ( Fig. 14 e); propodus with four movable spines (also four in paratypes ULLZ 6204, 6377 and four in USNM 237981) along ventrolateral surface. Fifth pereopod more slender than third and fourth ( Fig. 14 f), ischium lacking movable spine, merus similar in length to carpus and propodus; propodus with tufts of thick setae, lacking movable spines, setose along distal superior and ventral margins; dactylus simple, curved, narrowing to acute tip.

First to fourth abdominal somites in male with posterolateral angle of pleura rounded to weakly angular ( Fig. 12 a). Male second pleopod with appendix masculina subequal in length to appendix interna ( Fig. 12 f). Telson slightly tapering ( Fig. 12 g), length about 2.5 times as long as wide (medially), two pairs of dorsal movable spines, anterior pair inserted near 3/8, posterior pair near 5/8 length of telson; posterolateral margin broadly rounded, each posterolateral angle with two small movable spines, mesial larger than lateral ( Fig. 12 g). Uropodal exopod subequal in length to telson and endopod, lateral margin produced with subacute tooth adjacent to strong movable lateral spine; endopod broadly subovate, subequal in length to telson.

Gill formula typical for genus, including arthrobranch on third maxilliped, mastigobranch epipod on coxa of third maxilliped to fourth pereopod, setobranch on coxa of first to fifth pereopod.

Color ( Fig. 2 g–i). Carapace and abdominal somites marked by rust to pink-red isolated and interconnected chromatophores and color patches on brownish to whitish ground color; pigment cover especially dense on anterior margin of carapace lateral to orbital hoods, antennular peduncles, area encompassing rostral carina between eyes, and sixth abdominal somite, sometimes forming broad ill-defined dorsolateral bars or crescents on abdominal somites; chelae with broadly distributed patches of orange to rust brown pigment, poorly (if at all) defined into encircling bands; pereopods 3–5 with often diffuse reddish band on distal third of merus, and with broader less defined band of same pigment on carpus where most pigment is concentrated on extensor margin; eggs pale yellow to orange-brown.

Size. Largest examined male at cl 8.8 mm, tl 25.1 mm; largest female at cl 9.0 mm, tl 26.0 mm; egg diameter 0.30–0.45 mm.

Habitat. Most specimens were collected by trawls and dredges at a depth range of 24–100 m, on mud, silt, sand-mud-shell, and sand bottoms.

Distribution. Eastern Pacific: Gulf of California to Ecuador.

Type locality. Pacific coast of Costa Rica, west of Loma.

Etymology. Named for the fire-red color common in this species, in reference to the Greek mythology god Hephaestus , symbol of fire and craftsmanship, who was thrown from Mount Olympus and fell for many days until landing in the ocean near the island of Lemnos.

Remarks. Alpheus hephaestus sp. nov. is restricted to the eastern Pacific and has a unique color pattern that distinguishes it from all other species of the A. floridanus complex. Morphologically and genetically, A. hephaestus sp. nov. is most similar to A. platycheirus , from which it may be distinguished by the configuration of the orbital hoods, which extend well past the eyes and are more ovate to triangular in A. hephaestus sp. nov. ( Table 1 ), and by the generally shallower longitudinal furrow on the lateral surface of the major cheliped ischium in mature specimens.

Kim and Abele (1988) reported A. floridanus from Ecuador (Cape San Francisco, Ecuador, pg. 53–55, fig. 22 a–m), mentioning a movable spine on the ischium of the fifth pereopod and no spines on the propodus of the third and fourth pereopods. We re-examined Kim & Abele’s material (USNM 237981, 237990, 237989; 3 males, 1 female, sta. 216–34, 850–38) and found no spines on the ischium of the fifth pereopod; however, we did find them on the propodus of the third and fourth pereopods (usually 4 on each). Thus, the combination of morphological features and collection locality all suggest that the Ecuadorian material belongs to A. hephaestus sp. nov.

In their molecular analyses, Williams et al. (2001) identified two genetically distinct lineages allied with A. floridanus in the eastern Pacific (as “ A. floridanus sp. A - P” and “ A. floridanus sp. B - P”). However, these lineages were recovered only by cytochrome oxidase I (COI); other markers used in the analysis (elongation factor 1-alpha and GPI) were not sensitive enough to detect species level differences. Based on a genetic comparision of COI, GenBank sequences AF308987 and AF309901 of Williams et al. (2001) represent A. hephaestus sp. nov. The other eastern Pacific material (GenBank nos. AF308993 , AF309899 ) also cluster with A. hephaestus , and may represent a second species or population substructure within the eastern Pacific. However, the lack of resolution and unavailability of these specimens make definitive placement of these gene sequences ( AF308993 , AF309899 ) impossible (see Bracken & Felder, this volume for more details). It is noteworthy that Williams et al. (2001, table I) reported the habitat of “ A. floridanus sp. B - P” as “mud/rocks” as opposed to “mud” for " A. floridanus sp. A - P", indicating that the two lineages may be ecologically separated.

Figures

FIGURE 2. Color patterns of species allied to Alpheus floridanus Kingsley, 1878. Alpheus roblesi sp. nov.: a, b, dorsal and lateral views of male, cl 8.0 mm, Campeche Banks, Mexico (ULLZ 7197 A); c, lateral view of ovigerous female, cl 7.5 mm, Campeche Banks, Mexico (ULLZ 7197 B); d, dorsal view of female, cl 4.9 mm, Campeche Banks, Mexcio (ULLZ 7440). Alpheus ulalae sp. nov.: e, f, lateral view of holotype ovigerous female, cl 7.5 mm, northeastern Gulf of Mexico (USNM 1265092 = tissue / sequence ULLZ 6815). Alpheus hephaestus sp. nov.: g, lateral view of male, cl 9.1 mm, Pacific coast of Costa Rica (ULLZ 6204); h, dorsal view of male, cl 7.1 mm, Pacific coast of Panama (ULLZ 8004); i, dorsal view of male, cl 8.9 mm, Pacific coast of Panama (ULLZ 9508 A). Alpheus platycheirus Boone, 1927: j, dorsal view of damaged female, cl 7.9 mm, northern Gulf of Mexico (ULLZ 6421); k, dorsal view of ovigerous female, cl 9.0 mm, northern Gulf of Mexico (ULLZ 5858); l, dorsal view of male, cl 9.8 mm, northern Gulf of Mexico (ULLZ 5952).

FIGURE 12. Alpheus hephaestus sp. nov.: a – c, e – g, holotype male (USNM 1265093 = tissue / sequence ULLZ 6205); d, paratype ovigerous female (ULLZ 6377): a, habitus, lateral; b, anterior carapace, dorsal, setation not shown; c, anterior carapace, left side, lateral; d, right major cheliped, lateral; e, left minor cheliped, lateral; f, right second pleopod, appendix interna, and appendix masculina; g, sixth abdominal somite, telson and uropods, dorsal. Scale bars = 2.0 mm.

FIGURE 13. Alpheus hephaestus sp. nov.: a – f, holotype male (USNM 1265093 = tissue / sequence ULLZ 6205): a, right mandible, mesial; b, right maxillule, lateral; c, right second maxilla, lateral; d, right first maxilliped, lateral; e, right second maxilliped, lateral; f, right third maxilliped, lateral. Scale bars = 1.0 mm (a – e), 2.0 mm (f).

FIGURE 14. Alpheus hephaestus sp. nov.: a, c – e, f, holotype male (USNM 1265093 = tissue / sequence ULLZ 6205); b, g, paratype ovigerous female (ULLZ 6377): a, right major cheliped, lateral; b, left minor cheliped, lateral; c, right second pereopod, lateral; d, right third pereopod, lateral; e, right fourth pereopod, lateral; f, right fifth pereopod, lateral; g, abdomen, pleopods, and eggs, right side, lateral. Scale bars = 2.0 mm.