Alpheus ulalae, 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 : 466-469

Alpheus ulalae sp. nov.

( Figures 2 e, f; 9a–g; 10a–f; 11a–f)

Type material. NE Gulf of Mexico off Florida. Holotype: ovig. female, cl 7.5 mm ( USNM 1265092 = tissue/ sequence ULLZ 6815),, 28°10.01’N, 84°94’W, stn. NSF-III-054, box dredge, R/V Pelican, sandy mud, 41.4–41.7 m, 19 July 2006, D. Felder et al. Paratype: 1 male, cl 11.0 mm ( USNM 273137, specimen A of lot), 26°45.52’N, 83°21.26’W, trawl, Continental Shelf Associates, 50.2 m, 2 May 1981, P. McLaughlin.

Additional material. NE Gulf of Mexico off Florida: 3 males, 1 female ( USNM 273137, specimen B-E of lot), same collection data as paratype; Carribean Sea: 1 female (MNHN-IU-2013-12135), Guadeloupe, 16°22.57’N, 61°34.12’W, stn. GD02, Expedition: Karubenthos 2012, 80 m, 0 4 May 2012.

Description (based on holotype unless otherwise indicated). Carapace with narrow, acute rostrum not exceeding first article of antennular peduncle, median postrostral carina extending onto carapace midlength, flanked anteriorly by adrostral furrows reaching posteriorly to base of eyes ( Fig. 9 a–c); front projecting fully over eyes, ocular hood ovate, extending well beyond eye, unarmed; anterolateral margin of carapace weakly swollen adjacent to orbital hoods; pterygostomial angle distinct, rounded; cardiac notch deep.

Antennular peduncle (left side broken) first article with large ventromesial carina ending in acute tooth, first article about 3.2 times length of width, second article about 4.9 times length of width, third article about 1.9 length of width ( Fig. 9 b, c); mesial flagellum narrower than lateral (broken); distal ½ of lateral bearing aesthetascs; stylocerite broad, tapering into sharp tip, not over-reaching distal margin of first article. Antenna with stout basicerite bearing strong, sharp, ventrolateral tooth ( Fig. 9 b, c); antennal scale (scaphocerite) long, lateral margin distinctly concave, distolateral spine prominent, extending distinctly beyond rounded anterior margin of blade, over-reaching antennular peduncle by at least twice length of third article (2.7 in holotype, USNM 1265092 = tissue/sequence ULLZ 6815), distinctly overreaching carpocerite (9a, b, c).

Mandible (left) incisor process with five well-developed teeth, two enlarged, mostly confined to inferior half of cutting edge, superior margin dentition poorly defined ( Fig. 10 a); molar process rounded, blunt; palp twosegmented. Maxillule, maxilla, first and second maxilliped typical for genus (10b–e). Third maxilliped exopod slender, setose, not extending beyond antepenultimate article of endopod ( Fig. 10 f); endopod terminal article flattened, spatulate, densely covered by 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 ( Fig. 9 d–f); major cheliped ischium short; merus subrectangular, ventral surface flattened, with eight conspicuous movable spines (6 in paratype USNM 273137A) along ventromesial margin; carpus cup-shaped, lacking small subacute tooth protruding from ventromesial margin, major chela rectangular in shape, laterally compressed, elongate, lacking depressions or grooves, margins setose, chela length about 4 times height (in paratype USNM 273137A, length 3 times height), propodus length about 3 times dactylus length (in paratype USNM 273137A length 3 times dactylus length), mesial and lateral surface of palm smooth; dactylus setose, truncate distally. Minor cheliped missing in holotype, in paratype (USNM 273137A, Fig. 9 g) ischium short; merus subrectangular, ventral surface flattened, with seven movable spines (two broken) and sparse setae along ventromesial margin; carpus stout, distally cup-shaped; chela slender, long, lacking depressions or grooves, chela length about 4.3 times height, palm smooth, about 1.6 times as long as dactylus, linea impressa inconspicuous, fingers with long setae along margins, tips slightly crossing.

Second pereopod slender ( Fig. 11 a), ischium equal in length to merus; carpus composed of five articles with length ratio 1:1:1:3.6:2.5 (distal to proximal); chela simple, fingers slightly longer than palm, sparsely setose distally. Third pereopod robust ( Fig. 11 b–d), ischium armed with movable spine on ventrolateral surface; merus about twice as long as carpus; distal superior margin of carpus distinctly overhanging propodus; propodus slightly longer than carpus, single proximal movable spine on ventrolateral surface, long setae along entire superior and ventral margin, lacking dense tufts; dactylus simple, sub-ovate, slightly curved, narrowing to acute tip. Fourth pereopod ( Fig. 11 e) similar to third, shorter, more slender, propodus with two movable spines along proximal half of ventrolateral surface. Fifth pereopod more slender than third and fourth ( Fig. 11 f); ischium lacking movable spine; merus, carpus, and propodus subequal in length; propodus lacking movable spines, with long sparse setae along margins and fringe of comb-like setae along distoventral surface; dactylus simple, curved, triangular, narrowing to acute tip.

First to fourth abdominal somites in male paratype (USNM 273137) with posterolateral angle of pleura rounded to weakly angular. Male second pleopod with appendix masculina, slightly over-reaching appendix interna. Telson slightly tapering ( Fig. 9 h), length about 2.6 times as long as wide (medially), two pairs of dorsal movable spines, anterior pair inserted near 3/10, posterior pair near 5/10 length of telson; posterolateral margin broadly rounded, each posterolateral angle with two small movable spines, mesial larger than lateral ( Fig. 9 h). Uropodal exopod extending slightly beyond telson and endopod, lateral margin produced with subacute tooth adjacent to strong movable lateral spine; endopod broadly subovate, subequal in length to telson (9h).

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 pattern. ( Fig. 2 e–f). Abdominal somites marked by diffuse dorsal bands of small rose red to reddish orange chromatophores, densest on posterior of each somite ( Fig. 2 e, f); carapace anterior margin lateral to orbital hoods marked by narrow but distinct vertical slash of red color; lateral margin of antennal scale and peduncle with series of 6-7 red dash marks; major cheliped with reddish pigment dorsally on palm, carpus and distal merus, forming diffuse bands fading laterally; eggs bright yellow-green.

Size. Largest examined male at cl 11.0 mm, tl 31.0 mm (USNM 273137A); largest examined female at cl 11.0 mm, tl 24.0 mm (USNM 273137C); egg diameter 0.4 mm (measured in the holotype).

Habitat. Specimens were dredged from sandy mud bottoms, usually with shell fragments, at a depth range of 41– 80 m.

Distribution. Western Atlantic: continental shelf off western Florida, in the northeastern Gulf of Mexico and Carribean Sea ( Guadeloupe).

Type locality. Northeastern Gulf of Mexico, off Tampa Bay, Florida.

Etymology. The specific name “ ulalae ” is a feminine transformation of the abbreviation “ULALA,” a colloquial acronym representing the University of Louisiana at Lafayette.

Remarks. Alpheus ulalae sp. nov. is morphologically most similar to A. floridanus . In both species, the distal tooth of the antennal scale extends distinctly beyond the third article of the antennal peduncle, separating them from A. hephaestus sp. nov. and A. platycheirus . The shape of the antennal scale and absence of movable spines on the propodus of the fifth pereopod can be used to distinguish A. ulalae sp. nov. and A. floridanus from A. roblesi sp. nov. The position, robustness and number of spines on the propodus of the third and fourth pereopod separate A. ulalae sp. nov. from A. floridanus . Alpheus ulalae has 1–2 movable spines located on the proximal half of the propodus of the third and fourth pereopods. In contrast, A. floridanus has 3–5, (rarely more) movable spines along the entire ventrolateral surface of the propodus of the third and fourth pereopods. The two species may also be seprataed by the shape of the mandible incisor process ( Table 1 ): with strong dentition only on the inferior half of the distal cutting edge in A. ulalae sp. nov. vs. with strong dentition along the entire margin in A. floridanus .

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 9. Alpheus ulalae sp. nov.: a – d, h, holotype ovig. female (USNM 1265092 = tissue / sequence ULLZ 6815); e – g, paratype male (USNM 273137 A): a, habitus, lateral (minor chela missing); b, anterior carapace, dorsal; c, anterior carapace, left side, lateral; d, left major cheliped, lateral; e, right major chela, lateral; f, left major cheliped, mesial; g, left minor cheliped, lateral; h, abdominal somite six, telson, and uropods, dorsal. Scale bars = 2.0 mm.

FIGURE 10. Alpheus ulalae sp. nov.: a – f, holotype ovig. female (USNM 1265092 = tissue / sequence ULLZ 6815): a, left mandible, mesial; b, left maxillule, lateral; c, left second maxilla, lateral; d, left first maxilliped, lateral; e, left second maxilliped, lateral; f, left third maxilliped, lateral. Scale bars = 1.0 mm (b – e), 2.0 mm (a, f).

FIGURE 11. Alpheus ulalae sp. nov.: a – f, holotype ovig. female (USNM 1265092 = tissue / sequence ULLZ 6815): a, left second pereopod, lateral; b, left third pereopod, lateral (epipod not illustrated); c, dactylus of left third pereopod, dorsal; d, left third pereopod, carpus, propodus, dactylus, mesial; e, left fourth pereopod, lateral; f, left fifth pereopod, lateral. Scale bars = 2.0 mm.