Lysmata uncicornis Holthuis & Maurin, 1952

Pachelle, Paulo P. G., Carvalho, Leina, Alves, Douglas F. R. & Anker, Arthur, 2020, A revision of the Brazilian species of Lysmata Risso, 1816 (Decapoda: Caridea Lysmatidae), with discussion of the morphological characters used in their identification, Zootaxa 4789 (1), pp. 55-90 : 75-76

Lysmata uncicornis Holthuis & Maurin, 1952

( Figure 14 )

Lysmata uncicornis Holthuis & Maurin, 1952: 198 , figs. 1, 2; Lagardère 1971: 99, figs. 232–235; González-Ortegón et al. 2020: 26, figs. 1–4.

Lysmata arvoredensis Giraldes, Macedo, Brandão, Baeza & Freire, 2018: 5 , figs. 1–4.

Material examined. None.

First record for Brazil. Santa Catarina ( Giraldes et al. 2018, as L. arvoredensis ).

Distribution. Eastern Atlantic: Gulf of Cadiz ( Portugal and Spain), Africa ( Morocco to Congo) ( Holthuis & Maurin 1952; Lagardère 1971; González-Ortegón et al. 2020). Western Atlantic: Brazil (Santa Catarina, possibly São Paulo) ( Giraldes et al., 2018, as L. arvoredensis ; present study) ( Fig. 16 ).

Ecology. Brazil: rocky bottoms and possibly in mussel ropes, depth: around 20 m ( Giraldes et al., 2018, as L. arvoredensis ); eastern Atlantic: subtidal rocky bottoms ( Lagardère 1971) or “detritic bottom with rocks” (González- Ortegón et al. 2020).

Remarks. Lysmata uncicornis , despite having a distinctive colour pattern, can be easily confused with L. bahia due to similarities in some important taxonomic characters, such as the rounded pterygostomian angle, stylocerite length, shape and armature of the rostrum, and relative length between scaphocerite and antennular peduncle ( Figs. 3–4 , 14 ; see also Giraldes et al. 2018: figs. 1, 2, as L. arvoredensis ). However, these two species can be separated by the relative length of the first pereopod carpus (about three times as long as high in L. uncicornis versus over four times as long as high in L. bahia ) and the number of subdivisions in the second pereopod carpus (22–24 in L. uncicornis versus 29–31 in L. bahia ). In addition, the free portion of the accessory ramus of the lateral antennular flagellum is short in L. uncicornis and noticeably longer in L. bahia ( Fig. 4E, F ; Giraldes et al. 2018: fig. 2E), although the validity of character needs to be confirmed by examination of more material.

Lysmata uncicornis is also morphologically close to L. hochi Baeza & Anker, 2008 from the Caribbean Sea and Florida ( Baeza & Anker 2008; Baeza 2009), although phylogenetically these two species are not closely related (cf. Giraldes et al. 2018: fig. 5). As pointed out by González-Ortegón et al. (2020), some of the characters used by Baeza & Anker (2008) to separate L. hochi from L. uncicornis may not be valid due to the intraspecific variation in the latter species. However, the two species can still be separated by some details in their colour patterns, for instance, by the width of the transverse bands on the pleon, the disposition and shape of streaks and bands on the carapace and the presence/absence of white patches on the pleonites (cf. Baeza & Anker 2018: fig. 2 and González-Ortegón et al. 2020: fig. 3a, b). Noteworthy, the recent record of L. hochi from the Indian Ocean ( Jose et al. 2020) is likely erroneous since the colour pattern of the Lakshadweep specimens does not match that of L. hochi ; this record could refer to the closely related L. kuekenthali ( De Man, 1902) or yet another species.

A photograph of a shrimp extracted from a mussel rope in Caraguatatuba ( Fig. 14 ), taken by one of us (L. Carvalho) in 2012, suggests the presence of L. uncicornis also in the state of São Paulo. This individual presents a colour pattern that in all aspects is very similar to that of L. uncicornis in Giraldes et al. (2018 : figs. 1, 4F as L. arvoredensis ) and González-Ortegón et al. (2020: fig, 3a, b). Unfortunately, the photographed specimen could not be traced and therefore its true identity remains unknown.

Figures

FIGURE 3. Lysmata bahia Rhyne & Lin, 2006: non-ov. specimen from Bahia (pocl 11.6 mm; MZUSP 36972) in dorsal (A) and lateral (B) views. Scale bars: 10 mm. Photographs: P. Pachelle.

FIGURE 4. Lysmata bahia Rhyne & Lin, 2006, non-ov. specimen from Sergipe (pocl 12.0 mm; MZUSP 37511): (A) frontal margin and cephalic appendages, lateral view; (B) infraorbital region, lateral view; (C) same, dorsolateral view; (D) left third maxilliped, antepenultimate and penultimate articles, ventromesial view; (E) left antennule, third article of antennular peduncle and flagella, mesial view; (F) same, bifurcation between upper flagellum and accessory ramus, mesial view; (G) right first pereopod, merus to propodus, lateral view.

FIGURE 14. Lysmata uncicornis Holthuis & Maurin, 1952(?): non-ov. specimen from Caraguatatuba, São Paulo, in dorsal view. Voucher specimen not found. Photograph: L. Carvalho.

FIGURE 16. Distribution map for 11 species of Lysmata Risso, 1816 currently known from the Brazilian coast and offshore islands. Abbreviations: Alagoas (AL), Amapá (AP), Atol das Rocas (AR), Bahia (BA), Ceará (CE), Espírito Santo (ES), Maranhão (MA), Pará (PA), Paraíba (PB), Paraná (PR), Pernambuco (PE), Piauí (PI), Rio Grande do Norte (RN), Rio Grande do Sul (RS), Rio de Janeiro (RJ), Santa Catarina (SC), São Paulo (SP), São Pedro e São Paulo (SPSP), Sergipe (SE), Trindade e Martim Vaz (TMV).