Euryrhynchus tomasi De Grave, 2007,

Pachelle, Paulo P. G. & Tavares, Marcos, 2018, The freshwater shrimp family Euryrhynchidae Holthuis, 1950 (Crustacea: Decapoda: Caridea) revisited, with a taxonomic revision of the genus Euryrhynchus Miers, 1878, Zootaxa 4380 (1): 65-72

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Euryrhynchus tomasi De Grave, 2007


Euryrhynchus tomasi De Grave, 2007 

( Figs. 1EView FIGURE 1, 44BView FIGURE44, 45–49View FIGURE 45View FIGURE 46View FIGURE 47View FIGURE 48View FIGURE 49, 65AView FIGURE 65)

Euryrhynchus tomasi De Grave, 2007: 194  , figs. 1–7.

Euryrhynchus tomasi  — De Grave & Fransen 2011: 309; Pimentel & Magalhães 2014: 1302, fig. 2 [as E. burchelli Calman, 1907  , partim].

Material examined. Holotype: ♂ (cl 5.0 mm), NHM 2007.62View Materials, French Guiana, Cayenne , Ouanary , 20 km northwest of St Georges de l’Oyapock, Crique Timothy, approximately 04°00'N 51°52'W, coll. J. Tomas, 29.iii.2006.GoogleMaps 

Paratype: 1♀ (cl 6.5 mm), NHM 2007.63, same collection data as for the holotype.  Additional material: French Guiana: 1♂ (cl 4.1 mm), 1♀ (cl 5.0 mm), OUMNH.ZC.2015-02-007, Cayenne, Kourou, 15 km south of Kourou city, Montagne des Singes , 05.0718°N 52.6928°W, coll. O. Helke, 2012. BrazilGoogleMaps  : 8♂ (cl 5.1–4.0 mm), 2♀ (cl 4.9, 4.5 mm), 9♀ ov (cl 5.2– 4.6 mm), MZUSP 22766View Materials, Amapá, northwest of Amapá city, Vilarejo e Balneário Cachoeira Grande , in cave, 02°09'52.2''N 50°55'22.8''W, in submerged leaflitter, coll. J.M. Cunha & J. Zuanon, 06.iii.2007GoogleMaps  ; 1♂ (cl 4.2 mm), 1♀ov (cl 5.0 mm), OUMNH.ZC.2016-01-028, same collection data as previous lot; 2♂ (cl 3.2, 2.5 mm), 6♀ (cl 4.2– 2.6 mm), INPA 1082View Materials, Amapá, north of Amapá city, Rio Amapá Grande, Cachoeira Grande , small igarapé downstream, coll. C. Magalhães & Roberval, 26.viii.1992  .

Type locality. Crique Timothy , 20 km northwest of St Georges de l’Oyapock , Ouanary, Cayenne ( French Guiana). 

Distribution. French Guiana (Cayenne) and Brazil (Amapá) ( De Grave 2007; present study) ( Fig. 65AView FIGURE 65, green circles).

Description. De Grave (2007), figs. 1–7. The Brazilian material is illustrated on Figs. 45–49View FIGURE 45View FIGURE 46View FIGURE 47View FIGURE 48View FIGURE 49.

Remarks. Euryrhynchus tomasi  resembles E. burchelli  in having the second pereopod merus with a pair of spines on the distoventral angles ( Figs. 25DView FIGURE25, 46DView FIGURE 46), the third to fifth pleopods of female with appendix interna ( Figs. 29I –KView FIGURE 29, 48I –KView FIGURE 48), and the gonopods elongated, straight ( Figs. 29B, CView FIGURE 29, 30View FIGURE 30, 48B, CView FIGURE 48, 49View FIGURE 49). However, E. tomasi  can be easily recognized by (i) the second pereopod carpus with distomesial angle unarmed, smooth, Fig. 46DView FIGURE 46 (versus second pereopod carpus with 1 subdistal spine on the distomesial angle in E. burchelli  , Fig. 25DView FIGURE25), (ii) the second pereopod provided with fine granules at least on the surface of carpus and propodus, Fig. 46View FIGURE 46 (versus second pereopod without fine granules on surface of articles in E. burchelli  , Fig. 25View FIGURE25), and (iii) the fourth thoracic sternite with transversal ridge produced into prominent, triangular lobe medially, Fig. 45DView FIGURE 45 (versus fourth thoracic sternite with transversal ridge produced into low, broad lobe medially in E. burchelli  , Fig. 24DView FIGURE 24). According to De Grave (2007) the second to fifth pleopods lack appendix interna in the females. However, all female specimens examined during the present study, including the female paratype, do actually have appendix interna on the third to fifth pleopods ( Fig. 48I –KView FIGURE 48).

Pimentel & Magalhães (2014) reported three lots of E. burchelli  from Amapá, Brazil ( INPA 1082; IEPA 0 0 27, 0050). However, the specimens of the lot INPA 1082 actually belong to E. tomasi  (see remarks under E. burchelli  ), thus representing the first finding of the species in the Brazilian Amazon.


United Kingdom, London, The Natural History Museum [formerly British Museum (Natural History)]


Instituto Nacional de Pesquisas da Amazonia


Istituto di Entomologia Agraria dell'Universita














Euryrhynchus tomasi De Grave, 2007

Pachelle, Paulo P. G. & Tavares, Marcos 2018

Euryrhynchus tomasi

De Grave 2007: 194

Euryrhynchus tomasi

De Grave 2007

E. burchelli

Calman 1907