Alpheus ramosportoae, Soledade & Terossi & Scioli & Mantelatto & Almeida, 2019

Soledade, Guidomar O., Terossi, Mariana, Scioli, Justin A., Mantelatto, Fernando Luis & Almeida, Alexandre O., 2019, A new western Atlantic snapping shrimp of the Alpheus macrocheles group (Caridea, Alpheidae) revealed by morphological, molecular and color data, European Journal of Taxonomy 581, pp. 1-21 : 5-11

Alpheus ramosportoae sp. nov.

urn:lsid:zoobank.org:act:B9DFFA34-24DA-4672-8A56-A474B3406B71

Figs 1–4

Alpheus macrocheles – Ramos-Porto 1979: 118 , figs. 1–6 [not Alpheus macrocheles ( Hailstone, 1835) ].

(?) Alpheus macrocheles – Coelho & Ramos-Porto 1980: 135 ; 1995: 116 — Coelho et al. 1980: 55; 1986: 84 — Fausto Filho 1980: 113 — Ramos-Porto et al. 1996: 219 — Christoffersen 1998: 359 — Barros & Pimentel 2001: 21 — Guterres et al. 2005: 231, fig. 1 — Coelho et al. 2006: 51 — Coelho Filho 2006: 8 — Alves et al. 2008: 49 — Souza et al. 2011: 47 — Almeida et al. 2012: 27 — Soledade & Almeida 2013: 101 [not Alpheus macrocheles ( Hailstone, 1835) ].

Diagnosis

Rostrum without setae, reaching well beyond half length of first segment of antennular peduncle; scaphocerite with lateral margin slightly concave, lateral tooth strong, surpassing distal margin of blade; blade reaching middle of third article of antennular peduncle; distal tooth distinctly exceeding distal margin of peduncle. Major cheliped with ischium armed with four spiniform setae; ventromesial margin of merus with five spiniform setae similar in size and shape, spaced almost equidistantly along length of mesial surface of merus; dactylus flattened, laterally twisted, dorsally convex and slightly bulbous distally; plunger developed, with anterior surface distinctly angular. Minor cheliped with ischium armed with four spiniform setae; ventromesial margin of merus with seven spiniform setae similar in size and shape, spaced almost equidistantly along length of mesial surface of merus; dactylus with strong crest on extensor margin. Second pereiopod elongated, slender; ischium slightly longer than merus; carpus with five articles with ratio approximately equal to 4: 2: 1: 1.5: 2; distolateral margin of uropodal exopod with one mesial tooth and one lateral tooth adjacent to spiniform seta.

Etymology

The name of this new species is our tribute to the Brazilian carcinologist Dr Marilena Ramos-Porto, retired professor of the Universidade Federal Rural de Pernambuco, Recife. Dr Marilena contributed substantially to the knowledge of the caridean shrimps of the northern and northeastern Brazil.

Material examined

Holotype

BRAZIL • ♂; Pernambuco, off Recife , approximately 20 nautical miles from the coast, REC I, dredge 4; 8°08′51.5″ S, 34°34′08.0″ W; 65 m depth; 7 Feb. 2018; agglomerations of sponges, rhodoliths and calcareous algae; GenBank 16S gene MK918616 ; MOUFPE 19470 .

Paratypes

BRAZIL – Ceará • 1 ♂; Ceará, seamounts of the North Chain , REVIZEE NE III, stn 75A; 54 m depth; 7 Apr. 1998; calcareous algae; GenBank 16S gene MK918615 ; MOUFPE 13703 . – Pernambuco • 1 ♂; exact locality unknown; 31–33 m depth; 7 Mar. 1969; calcareous algae; MOUFPE 8826 • 2 ♂♂; exped. Pesquisador IV, stn 5; 54 m depth; 12 Apr. 1971; MOUFPE 8856 • 1 ♀; off Recife , REC I, dredge 6; 8°09′06.8″ S, 34°34′28.4″ W; 53 m depth; 7 Feb. 2018; rhodolite crevice; GenBank 16S gene MK918618 ; CCDB 6120 • 1 ♀ ov; off Recife , REC I, dredge 3; 8°08′44.2″ S, 34°34′23.2″ W; 55 m depth; 7 Feb. 2018; rhodolith crevice; GenBank 16S gene MK918617 ; MZUSP 39146 .

Additional material

BRAZIL – Amapá • 3 ♂♂; exped. GEOMAR II, stn 116; 81.5 m depth; 13 Sep. 1970; calcareous algae; MOUFPE 8848 – Pará • 1 ♂, 1 ♀ ov; exped. GEOMAR II, stn 2441; 1970; MOUFPE 8855 • 1 ♂, 1 ♀ ov; exped. GEOMAR II, stn 2528; 60 m depth; 1971; MOUFPE 8836 – Maranhão • 1 ♀; Tutóia, RV Almirante Saldanha , stn 1732A; 69 m depth; 30 Oct. 1967; calcareous algae; MOUFPE 8829 • 9 NI; RV Almirante Saldanha , stn 1750; 52 m depth; 6 Nov. 1967; calcareous algae; MOUFPE 8830 • 1 ♂, 1 ♀; São Luis, RV Almirante Saldanha , stn 1875; 49 m depth; 23 Apr. 1968; calcareous algae; MOUFPE 8831 • 1 NI; Tutóia, RV Almirante Saldanha , stn 1813; 83 m depth; 28 Nov. 1967; calcareous algae; MOUFPE 8837 • 1 ♀; RV Almirante Saldanha , stn 1751; 44 m depth; 6 Nov. 1967; calcareous algae; MOUFPE 8845 • 1 ♂; RV Almirante Saldanha , stn 1750; 52 m depth; 6. Nov. 1967; calcareous algae; MOUFPE 8847 – Ceará • 1 ♂; REVIZEE NE III, stn 72A; 2°4′48’’ S, 38°12′0’’ W; 8 Jun. 1998; MOUFPE 13647 .

Comparative material analyzed

Alpheus amblyonyx Chace, 1972

FRANCE – Guadeloupe • 1 ♂; KARUBENTHOS, stn GB20; 16 m depth; 18 May 2012; MNHN- IU-12112 • 1 ♀ ov; KARUBENTHOS, stn GB24; 16 m depth; 18 May 2012; GenBank 16S gene MK714203 ; MNHN-IU-12026 .

MEXICO • 1 NI; Quintana Roo, southeast of Arrecife Chinchorro; 28 Aug. 1990; GenBank 16S gene MK714201 ; UNAM-CNCR 21271 .

Alpheus macrocheles ( Hailstone, 1835)

ANGOLA • 3 ♀♀ (2 ov), 1 ♂; Cuanza River ; 31 Jan. 1949; RMNH. Crus.D. 7821 .

CAPE VERDE • 1 ♀ ov, 3 NI; “Tydeman” Cancap–VI, Cape Verde Islands exped., stn 6.109, off Santa Luzia ; 16°44′ N, 24°46′ W; 55–80 m depth; 16 Jun. 1982; calcareous algae; RMNH. Crus.D. 51345 • 1 ♂; Tarrafal Bay; 1959; MNHN 3163 .

FRANCE • 1 ♀; Roscoff; RMNH. Crus.D. 34508 • 1 ♂; Roscoff; RMNH. Crus.D. 29789 • 1 ♂; Guéthary; 27 Oct. 1947; RMNH. Crus.D. 1869 .

MOROCCO • 1 ♀; 33°50′ N, 07°07′ W; 25 Jan. 1956; RMNH. Crus.D. 34495 • 1 ♂; Témara; 1952; RMNH. Crus.D. 34496 • 1 ♂; Témara; 1954; RMNH. Crus.D. 34497 .

PORTUGAL – Azores • 1 ♂, 1 NI; stn 5.142; 108–118 m depth; 7 Jun. 1981; GenBank 16S gene MK714206 ; RMNH. Crus.D. 51342 . – Madeira • 1 ♂; Cais de Porto Novo ; 18 Aug. 1993; under rocks; RMNH. Crus.D. 42706 .

SPAIN – Canary Islands • 1 ♂; southeast of Lanzarote , stn 4.070; 41–50 m depth; 20 May 1980; sand and calcareous algae; GenBank 16S gene MK714207 ; RMNH. Crus.D. 51363 .

Description

CARAPACE. Smooth, frontal margin with well-developed sharp rostrum; orbital hoods with well-developed acute teeth originating from anterior margin of orbital hoods ( Fig. 1A ); rostrum slightly flattened dorsally, distinctly longer than wide, distally tapering and ending in acute point, without setae, reaching well beyond half-length of first article of antennular peduncle ( Fig. 1 A–B); margin between orbital teeth and rostrum V-shaped with slightly rounded angle ( Fig. 1A ); orbital process weak. Pterygostomial angle rounded, not anteriorly protruding ( Fig. 1B ); cardiac notch deep.

HEAD. Eyes with well-developed corneas; ocellar beak projecting, acute, visible in lateral view. Antennular peduncle moderately slender; stylocerite with acute tip reaching distal margin of first article of antennular peduncle; ventromesial carina with very large, triangular tooth bearing small acute point ( Fig. 1C ); second article of antennular peduncle much longer than visible part of first article, approx. three times longer than wide, twice as long as third article ( Fig. 1 A–B); lateral flagellum with several groups of aesthetascs extending to article 10. Antenna with basicerite ending in sharp ventrolateral tooth, extending just beyond orbital tooth; carpocerite slightly overreaching scaphocerite and antennular peduncle; scaphocerite with lateral margin slightly concave, ending in strong distolateral tooth distinctly overreaching antennal peduncle and surpassing distal margin of blade ( Fig. 1A ), latter reaching to middle of third article. Mouthparts typical for Alpheus , as illustrated ( Fig. 1 D–I). Third maxilliped slender; coxa with lateral plate slightly truncate distally; exopod overreaching antepenultimate article when extended; antepenultimate article somewhat flattened, approximately four times longer than wide, ventral surface sparsely setose; penultimate article about three times longer than wide, slightly broadened distally and densely setose; ultimate article unarmed, distally tapering, with dense transverse rows of long setae ( Fig. 1I ).

CHELIPEDS. Major cheliped with ischium short, robust, ventromesial surface with four small spiniform setae ( Fig. 2F ); merus robust, about twice as long as wide, subtriangular in cross-section; ventrolateral margin unarmed; ventromesial margin straight, bearing five small spiniform setae, ending in robust sharp tooth; carpus short, cup-shaped, slightly compressed ( Fig. 2F ); lateral surface of palm with low crest (inferior crest) starting at approximately 0.6 of palm length, ending in sharp distolateral tooth, latter slightly directed laterally ( Fig. 2A ); mesial surface convex, smooth, without grooves ( Fig. 2B ); ventral surface with rounded smooth shoulder slightly projecting into adjacent deep notch, latter extending transversely to groove on mesial surface (inferior groove); dorsal margin with subcylindrical elevation (plaque crest) ending distally in large adhesive disk; distomesial surface with deep transversally notched crest (superior crest) ending in sharp tooth; distal third of ventral margin with long, robust setae extending to distomesial margin; pollex shorter than dactylus, strongly curved laterally, cutting edge slightly excavate, bearing one small rounded tooth proximally ( Fig. 2A ); dactylus flattened, laterally twisted, dorsally convex, slightly bulbous distally ( Fig. 2A ); plunger moderately developed, its proximal margin with sharp angle ( Fig. 2E ); adhesive disks of dactylus well-developed ( Fig. 2A ). Minor cheliped not sexually dimorphic; ischium, short, stout, its distomesial margin armed with four spiniform setae; merus broad, subtriangular in cross-section; ventrolateral surface unarmed; ventromesial margin slightly convex, ending in small acute tooth, with seven spiniform setae similar in size and shape, spaced almost equidistantly along entire length of mesial margin; carpus cup-shaped ( Fig. 2G ); chela strongly compressed; palm with grooves and notches on distal half of lateral surface ( Fig. 2 C–D); lateral surface with low crest (inferior crest) starting at about middle of palm and ending in acute distolateral tooth ( Fig. 2C ); mesial surface convex and devoid of depressions or grooves ( Fig. 2D ); ventral surface smooth, ending in well-defined notch; dorsal margin also smooth, with sub-cylindrical elevation (plaque crest) ending distally in small adhesive disk; distomesial surface with high ridge ending in strong sharp tooth (superior crest); fingers as long as palm ( Fig. 2 C–D); pollex lightly excavate on cutting edge; dactylus slightly flattened and twisted laterally, with broad crest on extensor margin, bearing small adhesive disk proximally ( Fig. 2 C–D).

PEREIOPODS. Second pereiopod elongate, slender; ischium slightly longer than merus; carpus with five subdivisions with ratio approximately equal to 4: 2: 1: 1.5: 2; chela fingers as long as palm, with small tufts of setae on distal region ( Fig. 3A ). Third pereiopod with ischium armed with one strong spiniform seta on ventrolateral surface ( Fig. 3B ); merus five times longer than broad, unarmed distoventrally; carpus slender, about half-length of merus ( Fig. 3B ); propodus approximately 1.2 times as long as carpus, with about nine robust spiniform setae along ventral margin and one pair of spiniform setae at propodo-dactylar articulation ( Fig. 3E ); dactylus slightly shorter than half-length of propodus, conical, slightly curved, acute, extensor margin with one subdistal denticle ( Fig. 3E, H ). Fourth pereiopod similar to third in shape and proportion of articles, slightly less robust ( Fig. 3C ); ischium armed with one strong spiniform seta on ventrolateral surface ( Fig. 3C ); propodus with about eight robust spiniform setae along ventral margin and one pair of spiniform setae at propodo-dactylar articulation, extensor margin with one subdistal denticle ( Fig. 3F, I ). Fifth pereiopod more slender than third and fourth ( Fig. 3D ); merus slightly longer than carpus; ischium with one spiniform seta; propodus with about eight spiniform setae along ventral margin and nine well-developed rows of setae distolaterally (omitted) ( Fig. 3G ).

PLEON. Pleonites 1–4 with posteroventral margins broadly rounded, fifth pleonite slightly angular. Telson subrectangular, tapering to posterior margin; proximal margin twice as wide as distal margin; lateral margin slightly convex; dorsal surface with two pairs of spiniform setae, first pair located at telson halflength, second pair at approximately 0.7 of telson length; posterior margin broadly convex, with two pairs of spiniform setae, mesial pair about three times as long as lateral pair ( Fig. 1J ); anal tubercles well-developed.

PLEOPODS. With sparse setae on lateral margin of protopod. First pleopod reduced; distal margin of endopod with setae. Second pleopod of male with appendix masculina subequal in length to appendix interna, not reaching distal margin of endopod, with numerous rigid setae distally. Uropod with lateral lobe of protopod ending in strong sharp tooth ( Fig. 1J ); diaeresis sinuous; distolateral margin of exopod with one mesial tooth and one lateral tooth flanking spiniform seta ( Fig. 1K ); endopod with row of spiniform setae along distal margin, mesial ones stronger than lateral ones ( Fig. 1L ).

Color in life

Body predominantly reddish; carapace uniformly reddish; pleon reddish with whitish transverse bands and whitish spots on lateral surface; major cheliped palm reddish, with three transverse white patches on both lateral and mesial surfaces, more defined on mesial surface; fingers of both chelae reddish; telson and uropods intensely reddish; protopods of uropods whitish; pereiopods (2–5) pale reddish ( Fig. 4 A– C). This color pattern was homogeneous in all specimens collected.

Habitat

On sand mixed with calcareous algae, rhodoliths and sponges ( Fig. 4 D–F), at depths ranging from 33 to 90 m ( Ramos-Porto 1979, as A. macrocheles ; present study).

Distribution

Brazil: Amapá, Pará, Maranhão, Ceará and Pernambuco ( Ramos-Porto 1979, as A. macrocheles ; present study).

Molecular analysis

The best-fit substitution model selected with a corrected Bayesian information criterion was TPM3uf+I, assuming the nucleotide frequencies A = 0.2847, C = 0.1194, G = 0.2561, T = 0.3398, replacement rates AC = 0.0010, AG = 4.5910, AT = 1, CG = 0.0010, CT = 4.5910, GT = 1, proportion of invariable sites = 0.5410. The Bayesian Inference analysis ( Fig. 5 ) retrieved two clades, one being formed by A. amblyonyx and another including A. ramosportoae sp. nov. as sister to a clade formed by A. crockeri (Armstrong, 1941) , A. puapeba and A. macrocheles . Genetic distance estimates ( Table 2 ) support these results. The range of the genetic distance values between A. ramosportoae sp. nov. and other species was 15.9–22.9% according to the TPM3 model. Alpheus ramosportoae sp. nov., as well as A. amblyonyx and A. macrocheles , show no significant intraspecific divergence in 16S sequences.

Figures

Fig. 1. Alpheus ramosportoae sp. nov. A–D. Holotype, ♂, from off Recife, state of Pernambuco, northeastern Brazil (MOUFPE 19470). A. Carapace and cephalic appendages, dorsal view (setae omitted). B. Same, lateral view. C. Tooth on ventromesial carina of antennular peduncle. D. Left mandible, mesial view. E–L. Paratype, ♂, from seamounts of the North Chain, Ceará, northeastern Brazil (MOUFPE 13703). E. First maxilla, lateral view. F. Second maxilla, lateral view. G. First maxilliped, lateral view. H. Second maxilliped, lateral view. I. Third maxilliped, lateral view. J. Telson and uropods, dorsal view (setae omitted). K. Uropod, detail of the distolateral angle of the exopod. L. Uropod, detail of the posteerior margin of endopod. Scale bars: A–B, J = 1 mm; C–I, K–L = 0.5 mm.

Fig. 2. Alpheus ramosportoae sp. nov., paratype, ♂, from seamounts of the North Chain, Ceará, northeastern Brazil (MOUFPE 13703). A. Major cheliped, lateral view. B. Same, mesial view. C. Minor cheliped, lateral view. D. Same, mesial view. E. Major chela dactylus, mesial view, detail of plunger. F–G. Detail of spiniform setae on ischium and propodus of major and minor chelae, respectively. Scale bars: A–E = 1 mm; F–G = 0.5 mm.

Fig. 3. Alpheus ramosportoae sp. nov., paratype, ♂, from seamounts of the North Chain, Ceará, northeastern Brazil (MOUFPE 13703). A. Second pereiopod, lateral view. B. Third pereiopod, lateral view. C. Fourth pereiopod, lateral view. D. Fifth pereiopod, lateral view. E–G. Third to fifth pereiopods, detail of propodus, lateral view. H–I. Third and fourth pereiopods, detail of dactylus. Scale bars: A–G = 0.5 mm; H–I = 0.25 mm.

Fig. 4. Alpheus ramosportoae sp. nov. from off Recife, state of Pernambuco, northeastern Brazil. A–C. Color pattern in life of the species. A. Body color pattern, lateral view. B. Coloration of major (mesial view) and minor (lateral view) chelipeds. C. Coloration of pleon, lateral view. D–F. Substrates where the specimens were obtained. D. Calcareous algae, sponges and sandy sediment clusters. E. External appearance of rhodolith fragments. F. Detail of a fragment of rhodolith broken in half, showing crevices from which specimens were retrieved. Scale bars: A–C = 1 mm; D–F = 2 cm.

Fig. 5. Bayesian Inference Tree of the 16S gene including specimens of Alpheus ramosportoae sp. nov., selected species of the A. macrocheles complex, and Synalpheus C.S. Bate, 1888. Numbers close to nodes represent posterior probabilities. Abbreviations: CE = state of Ceará; PE = state of Pernambuco.