Boreas uglowi Cumberlidge & Sternberg 2002, n. sp.
Creators: name: Cumberlidge, Neil
name: Sternberg, Richard V.
Publisher: name: Zenodo
Year: 2002
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Potamonautidae
Boreas
Boreas uglowi

description: Boreas uglowi n. sp.   
(Fig 2D; 3G; 4L; 5H; 6L; 7Q, R; 8E; 10A, B; 11L)  
 Madagapotamon ankaraharae – Bott 1965 (part): 347, 348, fig. 9d, e, pl. 5, figs 23-25 (non fig. 9a-c).   
 MATERIAL EXAMINED. — Madagascar. Nosy-Bé, Madagascar, 1 ad., holotype cw 29.3, cl 21.3, ch 10, fw 8.5 mm (MNHN-B 12292). — Diego-Suarez (now Antsiranana), coll. J. Millot, 1 ad. cw 24.3, cl 18.8, ch 8.6, fw 7.6 mm (MNHN-B 5028). — Nosy-Bé, Autumn 1927, coll. J. Millot, 1 ad., cw 19.8 mm, broken in pieces (MNHN-B 5029). — Nosy-Bé, X.1922, coll. J. Millot, 1 ad. cw 25 mm, carapace damaged (MNHN-B 26147). — Nosy Komba, 500 m altitude, on a path, XII.1922, coll. J. Millot, 1 subadult cw 22, cl 16, ch 8, fw 6.5 mm, 1, broken cw 28.5, cl 19.5 mm, 1 juv. cw 18, cl 13.5, ch 6, fw 5 mm (MNHN-B 12293).   
TYPELOCALITY. — Nosy-Bé, Madagascar.  
ETYMOLOGY. — The species is named for Dr. Roger Frederick Uglow, Department of Applied Biology, University of Hull, U.K., in recognition of his prolific contributions to decapod crustacean physiology.  
DISTRIBUTION. — Madagascar, Nosy-Bé (Fig. 11L).  
DIAGNOSIS. — As for genus.  
DESCRIPTION  
Carapace outline transversely oval (wider than long, cw/fw = 3.2, cl/fw = 2.3), moderately arched (ch/fw = 1.1); epigastric, postorbital crests faint, not fused; postorbital crests not meeting anterolateral margins; exorbital, epibranchial teeth similar, both low, blunt, continuous with anterolateral margin; anterior regions of carapace surface smooth; anterolateral, posterolateral regions with short carinae; semi-circular, urogastric grooves deep; cervical grooves very short. Suborbital margin raised, faintly granulated. Front highly deflexed; frontal margin smooth, straight; frontal, posterior margins of carapace wide (cw 0.3 mm). Suborbital, subhepatic, regions of carapace sidewall smooth or with faint granules; pterygostomial region smooth with sparse short setae or a few small granules near third maxilliped. Carapace sidewall in three parts; distinct vertical sulcus on sidewall running from epibranchial tooth to longitudinal (epimeral) groove, dividing suborbital, hepatic regions.  
Mandibular palp two-segmented, terminal segment with flat basal thickening at junction between segments; ischium of third maxilliped smooth, vertical sulcus either faint or completely absent; exopod of third maxilliped medium length, reaching only proximal part of merus, exopod with long flagellum. Thoracic sternal sulcus s1/s2 not visible; sternal sulcus s2/s3 deep, horizontal; sternal sulcus s3/s4 reduced to two short side notches; anterior sternum smooth; episternal sulci s4/e4, s5/e5, s6/e6, s7/e7 smooth, no groove visible. Male abdomen slim, triangular.  
Gonopod 1 terminal article straight, slim, short (ratio length terminal article to subterminal segment 0.25), tip directed weakly outward, longitudinal groove clearly visible on ventral, superior sides, not visible on dorsal side; terminal article/ subterminal segment junction distinct, with narrow dorsal membrane; lateral, medial folds of ventral side of terminal article equal in height, width. Gonopod 2 longer than gonopod 1; gonopod 2 terminal article medium flagellum, ratio length gonopod 2 terminal article to subterminal segment 0.6.  
Dactylus of right, left chelipeds relatively narrow (one-quarter height of palm), upper margin smooth, finger of dactylus curved; slim interspace between closed fingers; finger of propodus onethird height of palm lower margin of propodus of cheliped slightly indented. Dactylus with series of small teeth interspersed by larger teeth; finger of propodus of right cheliped with large fused molar tooth. Anterior, posterior inferior margins of ischium of p1 smooth. Inferior margins of merus faintly granulated, distal margin with single low distal meral tooth; superior margin of merus with row of granules. First carpal tooth of carpus of cheliped large, wide, with pointed tip; second carpal tooth small. With pointed tip, followed by small granules. Anterior, posterior margins of propodi of p5 slightly serrated. Walking legs (p2- p5) normal length, neither elongated nor shortened, ratio length merus p5 to cw 0.3. P5 propodus short, broad, margins serrated; dactylus of p5 short, half length of dactylus of p2-p4.  
REMARKS  
 The generic assignment and validity of Potamon (Geothelphusa) ankaraharae remains uncertain. Nobili’s (1906) type is unavailable and the figures of the type in Bott (1965: fig. 9a-c) do not show the mandible or first gonopod. It should be noted that the male specimen cw 28 mm (MNHN Paris, no number provided) labeled M. ankaraharae in Bott (1965: fig. 9d, e, pl. 5 figs 23-25) from Diego-Suarez (now Antsiranana) was not part of the type series from Ankarahara, and probably does not represent this taxon. We consider it likely that this specimen was misidentified, and that it may not actually belong to the same species as P. (G.) ankaraharae sensu Nobili, 1906. Although Bott (1965) did not provide a catalogue number, it is likely that the specimen from Diego-Suarez (MNHN-B 28) is the same one that was used (in part) in the redescription of M. ankaraharae by Bott (1965: pl. V, figs 23-25, fig. 9e, f). For this reason, the illustrations of gonopods 1 and 2 in Bott 1965 (fig. 9d, e), the photographs of the whole animal (pl. V, figs 23- 25), and the text description of the mandibular palp as simple, may describe these structures in B. uglowi n. gen, n. sp., rather than P. (G.) ankaraharae sensu Nobili, 1906. This means that the gonopods and mandible of P. (G.) ankaraharae sensu Nobili, 1906, still await description.   
 Characters of the carapace, thoracic sternum and walking legs of B. uglowi n. gen, n. sp. are similar to those shown in the figures of the type of P. (G.) ankaraharae provided by Bott (1965). The two taxa have a similar carapace outline and texture and walking legs of similar proportions. The two taxa can be distinguished by examination of the ischium of the third maxilliped, which has a deep vertical groove in P. (G.) ankaraharae, but which is characteristically faint or lacking in B. uglowi n. gen, n. sp. The specimens from northern Madagascar from Diego-Suarez (MNHN-B 5028), Nosy-Bé (MNHN-B 5029) and (MNHN-B 26147), and Nosy Komba (MNHN-B 12293) that were formerly identified as P. (G.) ankaraharae are included here in the new taxon, because they resemble B. uglowi n. gen, n. sp. very closely. These specimens differ from B. uglowi n. gen, n. sp. in the texture of the pterygostomial region of the carapace sidewall, which is smooth in B. uglowi n. gen, n. sp. and distinctly setose in these other specimens.
description: Published as part of Cumberlidge, Neil & Sternberg, Richard V., 2002, The freshwater crabs of Madagascar (Crustacea, Decapoda, Potamoidea), pp. 41-79 in Zoosystema 24 (1) on pages 75-77, DOI: 10.5281/zenodo.5401510