Salmoneus wehrtmanni, Anker, 2010

Anker, Arthur, 2010, The shrimp genus Salmoneus Holthuis, 1955 (Crustacea, Decapoda, Alpheidae) in the tropical western Atlantic, with description of five new species *, Zootaxa 2372 (1), pp. 177-205 : 193-197

publication ID

https://doi.org/ 10.11646/zootaxa.2372.1.18

persistent identifier

https://treatment.plazi.org/id/2554563E-FF97-FB0C-A780-F96E03D5F813

treatment provided by

Felipe

scientific name

Salmoneus wehrtmanni
status

sp. nov.

Salmoneus wehrtmanni sp. nov.

( Figs. 10–11 View FIGURE 10 View FIGURE 11 , 12a View FIGURE 12 , 13b View FIGURE 13 , 14d View FIGURE 14 )

Type material. Holotype: breeding female (cl 5.0 mm, tl 14.0 mm), USNM 1124215 View Materials , Panama, Caribbean coast, Isla Grande, southern shore, under rocks and rubble on sand, near seagrass, 0.5–1 m depth, leg. A. Anker, 21.IV.2006 [fcn 06-395] . Paratypes: 1 breeding female (cl 4.2 mm, tl not measured), FLMNH UF Arthropoda 15019, Panama Caribbean coast, Isla Grande, off west point, under rock, 1.5 m depth, leg. A. Anker, 15.IX.2007 [fcn 07-252]; 1 non-breeding specimen (cl 3.3 mm, tl 9.0 mm), USNM 1124216 View Materials , Panama, Caribbean coast, Isla Grande, northeastern (sea side) shore, shallow bay below light house, 0.5 m depth, under rocks/rubble, leg. A. Anker, 5.IX.2006 [fcn 06-448, dissected]; 1 non-breeding specimen (cl 2.7 mm, tl 7.3 mm), USNM 1124217 View Materials , same collection data as previous specimen [fcn 06-449] .

Additional material examined. 1 non-breeding specimen (cl 3.7 mm), USNM 1124218 View Materials , Panama, Caribbean coast, Bocas del Toro, Isla Colón, Boca del Drago , under rocks on sand, 0.7–1.5 m depth, leg. A. Anker, 11.XI.2006 [fcn 06-618]; 2 breeding females (cl 2.3 mm, 2.4 mm), UP, Panama, San Blas Islands, small cay in the Cayos Los Grullos NE of Cartí Suitupo, 0.5–1.5 m depth, under rocks on coarse sand, leg. A. Anker & I. Marin, 22. V.2007 [fcn 07-178]; 1 breeding female (cl 3.0 mm), USNM 1124219 View Materials , Panama, Caribbean coast, La Guaira, in or under coral rocks, 0.5–1 m depth, leg. A. Anker, 4.VIII.2007 [fcn 07-213]; 1 breeding female (cl 4.9 mm, tl 12.3 mm), OUMNH 2007-20 - 149 , Honduras, Utila, Little Bight , 16°04.757'N 86°55.757'W, hand collecting, under rocks, 10 m depth, leg. A. Anker & S. De Grave, 8.VII.2007 GoogleMaps ; 1 breeding female (cl 5.1 mm), USNM 136103 View Materials , Mexico, Caribbean coast, Yucatan, Quintana Roo, Bahía de Ascensión, behind central part of Nicchehabin Reef , Smithsonian-Bredin Expedition St. 82–60, 0.6–1.3 m depth, leg. W.L. Schmitt, E.L. Bousfield & H.A. Rehder, 16.IV.1960 [with note “infested with abdominal bopyrid”, latter apparently removed]; 1 breeding female (cl 4.0 mm), USNM 136106 View Materials , Mexico, Caribbean coast, Yucatan, Quintana Roo, Bahía de Ascensión, Nicchehabin Reef , turtle grass and Porites clumps, Smithsonian-Bredin Expedition St. 91–60, leg. F.C. Daiber, E.L. Bousfield & R. L. Haynes, 18.IV.1960 ; 1 non-breeding subadult specimen (cl 2.1 mm), USNM 1125418 View Materials , Tobago, Sandy Bay , St. 5, rock washing, leg. R. Heard, 7.IV.1992 ; 1 breeding female (cl 3.2 mm), 1 non-breeding specimen (cl 3.4 mm), USNM 1125419 View Materials , Tobago, Lovers Beach, St. 3, leg. R. Heard, 6.IV.1992 .

Description. Carapace with numerous scattered setae ( Figs. 10a–b View FIGURE 10 , 12a View FIGURE 12 ). Rostrum triangular in dorsal view, usually as long as broad at base, reaching well beyond mid-length of second segment of antennular peduncle, tip acute or subacute ( Figs. 10a View FIGURE 10 , 12a View FIGURE 12 ); lateral margins nearly straight; ventral margin unarmed ( Fig. 10b View FIGURE 10 ); rostral carina well marked, extending beyond level of eyes posteriorly, areas lateral to rostral carina shallowly depressed ( Figs. 10a View FIGURE 10 , 12a View FIGURE 12 ). Orbital teeth strong, acute ( Figs. 10a View FIGURE 10 , 12a View FIGURE 12 ). Pterygostomial margin not protruding anteriorly, rounded-angular ( Fig. 10b View FIGURE 10 ). Eyes completely concealed in dorsal and lateral views ( Figs. 10a–b View FIGURE 10 , 12a View FIGURE 12 ); cornea well developed; anteromesial margin of eyestalk not especially projecting.

Antennule with stylocerite distinctly overreaching distal margin of second peduncular segment, with acute tip; ventromesial carina of first segment with small sharp tooth ( Fig. 10c View FIGURE 10 ); second segment not elongate, wider than long ( Fig. 10a View FIGURE 10 ); lateral flagellum bifurcating at second segment, secondary ramus well developed, with several groups of aesthetascs ( Fig. 10a View FIGURE 10 ). Antenna with basicerite bearing stout acute distoventral tooth ( Fig. 10b View FIGURE 10 ); scaphocerite broadly ovate, with strong acute distolateral tooth and broad blade, latter with feebly convex anterior margin ( Fig. 10a View FIGURE 10 ); carpocerite short, not reaching mid-length of scaphocerite.

Third maxilliped with short, rounded lateral plate; ultimate segment tapering, tip with small spines ( Fig. 10d View FIGURE 10 ).

Chelipeds strongly asymmetrical in shape, unequal in size ( Figs. 11a, d View FIGURE 11 ). Major cheliped ( Figs. 11a–c View FIGURE 11 ) with ischium unarmed; merus inflated, especially distally, excavated ventrally; carpus somewhat elongate, with depressed ventral margin; chela stout, with fingers slightly longer than half-length of palm; palm conspicuously flattened ventromesially, more excavated proximally, sparsely setose; fingers rather stout, straight except for curved crossing tips, cutting edges serrated, with around 10 subtriangular to rounded teeth ( Fig. 11c View FIGURE 11 ). Minor cheliped ( Fig. 11d View FIGURE 11 ) with ischium subequal to merus, unarmed; carpus 0.8 length of merus, cylindrical, widening distally; chela small, simple, with fingers shorter than palm, cutting edges unarmed.

Second pereiopod ( Fig. 10e View FIGURE 10 ) relatively short, slender; ischium unarmed; merus shorter than ischium; carpus five-segmented, first segment approximately equal to sum of third, fourth and fifth segments. Third pereiopod ( Fig. 10f View FIGURE 10 ) slender; ischium with one ventrolateral spine; merus about five times as long as wide; carpus with small distoventral spinule; propodus with three small ventral spinules and longer and stouter distal spinule(s); dactylus simple, conical, moderately slender, slightly less than half-length of propodus. Fourth pereiopod similar to third. Fifth pereiopod with ischium unarmed; propodus with setal brush distally.

First to third pleura rounded; fourth pleuron ending posteriorly in blunt angle; fifth pleuron forming blunt angle posteroventrally ( Fig. 10g View FIGURE 10 ); sixth pleurite without distinct articulated plate, however, feeble suture delimiting subtriangular posteroventral projection; preanal plate triangular, rounded distally. Telson ( Fig. 10j View FIGURE 10 ) about twice as long as wide proximally, tapering posteriorly, with two pairs of dorsal spines situated first at or slightly posterior to telson mid-length, second at about 0.8 telson length; posterior margin straight in dorsal view, central portion with inconspicuous, broadly V-shaped incision (better visible in ventral view) and three pairs of thick plumose setae, latter fringed by two pairs of spines, lateral being only half as long and less than stout than mesial.

Second pleopod with appendix masculina slightly shorter than appendix interna, furnished with stout setae apically and on inner margin ( Fig. 10h View FIGURE 10 ). Uropod ( Fig. 10i View FIGURE 10 ) with narrow exopod and endopod; diaeresis sinuous; both distolateral tooth and adjacent distolateral spine very stout.

Gill/exopod formula typical for genus (see under first species).

Size. cl 2.3–5.0 mm, tl of largest specimens: 14.0 mm (holotype), 12.3 mm (breeding female from Utila).

Colour in life. Semitransparent, milky white, with slight pale tinge and hyaline chelae; embryos yellow ( Fig. 14d View FIGURE 14 ).

Etymology. Named for Ingo S. Wehrtmann (Universidad de Costa Rica), a good friend and colleague, and a specialist of reproduction in decapods and other crustaceans.

Type locality. Isla Grande, Panama.

Distribution. Presently known from several localities on the Caribbean coast of Panama (Isla Grande, La Guaira, San Blas Islands, Bocas del Toro), Honduras (Utila), Mexico (Quintana Roo), and Tobago.

Ecology. Near-shore silty sandy flats, often near seagrass and mangrove roots, under rocks and rubble at shallow depths (0.5–1.5 m).

Variation. The specimen from Utila agrees well with the specimens from Panama except for a small difference in the length of the posterior spines on the telson: in the Utila specimen, both pairs are stout and subequally long (S. De Grave, pers. comm.), whereas in the holotype, the lateral spines are significantly shorter and slenderer ( Fig. 10j View FIGURE 10 ). The Quintana Roo and Tobago specimens show some variation in the length of the rostrum and strength and direction of the orbital teeth. In smaller specimens, the rostral carina is usually less distinct.

Remarks. Salmoneus wehrtmanni sp. nov. is belongs to the exclusively American S. ortmanni species group ( Anker & Marin 2006; see also above), being closely related to the other two species of this group, S. ortmanni and S. carvachoi . Rankin’s type of S. ortmanni (originally described as “ Athanas ortmanni ”) from Nassau in the Bahamas is nowhere to be found. Rankin’s single figure of S. ortmanni is just informative enough to know that it is distinct from S. carvachoi (see Anker 2007).

Anker (2007) provided illustrations of S. ortmanni from Atol das Rocas off NE Brazil, which agree well with figures provided by Schmitt (1936: figs. 2i, h; frontal margin, reproduced here in Fig. 12f View FIGURE 12 ) and Banner & Banner (1981: figs. 7h–k, major cheliped). Without the type specimen or topotypical specimens at hand, it seems most reasonable to accept the identity of S. ortmanni sensu Rankin (1898) as the most common and widespread species in reef, lagoon and shore habitats of the tropical western Atlantic, ranging from Bermuda south to Brazil and throughout the Caribbean, and therefore, there would seem to be little doubt that specimens illustrated by Schmitt (1936) and Anker (2007) were correctly identified as S. ortmanni .

The morphological differences between S. ortmanni and S. wehrtmanni sp. nov. are rather slight and can only be seen in adult specimens. In S. ortmanni , the basal portion of the lateral margin of the rostrum, as seen in dorsal view, is slightly convex, whilst the rostral carina is either absent or extends only to the level of the eyes. In contrast, in S. wehrtmanni sp. nov., the lateral margin is either straight proximally or broadly and slightly concave from the base of the rostrum all the way to the tip, whilst the rostral carina is stronger and reaches well beyond the eyes. In addition, the area adjacent to the rostral carina is not depressed in S. ortmanni , but is shallowly depressed in S. wehrtmanni sp. nov.; especially in larger specimens (compare Figs. 10a View FIGURE 10 , 12a, 12b–d View FIGURE 12 ; see also Anker 2007: fig. 1b). The orbital teeth appear to be somewhat stronger in S. wehrtmanni sp. nov. (compare Figs. 12a and 12b–d View FIGURE 12 ).

Some other differences between the two species were initially recorded while comparing side by side the Panamanian specimens of S. ortmanni and S. wehrtmanni sp. nov. However, these differences appear to be more ambiguous, especially when material from other places is included. For instance, in S. ortmanni , the posterior margin of the telson bears a rather conspicuous, more or less U-shaped notch ( Anker 2007, fig. 1j); in S. wehrtmanni sp. nov., this margin appears to be straight in dorsal view ( Fig. 10i View FIGURE 10 ), although observed in ventral view, it actually has a very shallow, broadly triangular incision (obscured by three pairs of plumose setae). In some specimens of S. wehrtmanni sp. nov., the first carpal segment is about four times as long as wide ( Fig. 10e View FIGURE 10 ), whereas in all S. ortmanni , the first carpal segment is always around six times as long as wide ( Fig. 13a View FIGURE 13 ; see also Anker 2007, fig. 1f). However, in some specimens from Yucatan assigned here to S. wehrtmanni sp. nov., this ratio approaches that of S. ortmanni , although the entire second pereiopod appears to be slightly more robust than in S. ortmanni ( Fig. 13 View FIGURE 13 ). Another possible difference between S. wehrtmanni sp. nov. and S. ortmanni lies in the carapace pilosity: S. wehrtmanni sp. nov. has distinctly more short stubby setae on the carapace ( Fig. 10b View FIGURE 10 ) than S. ortmanni , in which the carapace bears relatively few setae, and at first glance appears almost glabrous ( Figs. 12b–c View FIGURE 12 ). Interestingly, this distinction is only very clear in the Panamanian material; for instance, in the Bermuda specimen identified here as S. ortmanni based on the shape of the frontal margin, the carapace is covered by conspicuous setae; these setae are also present in the Atol das Rocas specimens ( Anker 2007, fig. 1c).

Importantly, on the Caribbean coast of Panama, where fresh material of both S. wehrtmanni sp. nov. and S. ortmanni was available, these two species can be easily distinguished when alive: the former species is pale milky white ( Fig. 14d View FIGURE 14 ), whereas the latter species is uniform yellow-orange ( Fig. 14e View FIGURE 14 ). Both S. ortmanni and S. wehrtmanni sp. nov. may occur sympatrically in similar habitats — shallow back reef flats with abundant rocks and rubble, often with Thalassia . Interestingly, in Bocas del Toro where both species occur, they were always collected at different locations: S. wehrtmanni sp. nov. at sand-rubble patches of Boca del Drago, with more fine sediments, and S. ortmanni at the more exposed and rockier parts of Playa Bluff.

Salmoneus carvachoi differs from both S. ortmanni and S. wehrtmanni sp. nov. in the long slender dactyli on the third to fifth pereiopods (see Anker 2007: fig. 3k) and also in its banded colour pattern ( Fig. 14f View FIGURE 14 ). In addition, S. carvachoi usually occurs on silt- and mud-type bottoms, e.g. in mangrove and estuarine habitats.

FLMNH

Florida Museum of Natural History

UF

Florida Museum of Natural History- Zoology, Paleontology and Paleobotany

UP

University of Papua and New Guinea

V

Royal British Columbia Museum - Herbarium

R

Departamento de Geologia, Universidad de Chile

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

Family

Alpheidae

Genus

Salmoneus