Foza ambohitra, Cumberlidge & Meyer, 2009

Cumberlidge, Neil & Meyer, Kristin, 2009, A new species of Foza Reed & Cumberlidge, 2006 from northern Madagascar (Decapoda, Brachyura, Potamoidea, Potamonautidae), with a redescription of F. goudoti (H. Milne Edwards, 1853) comb. n., and comments on Skelosophusa prolixa Ng & Takeda, 1994, ZooKeys 18 (18), pp. 77-89 : 79-84

Foza ambohitra sp. n.

urn:lsid:zoobank.org:act:1007E7DF-D87E-41A9-AB9D-B3628DB72C7D

( Figs 1–3 , Table 1 )

Type material. Holotype: adult male (CW 39.5, CL 32.4, CH 16.3, FW 8.7) northern Madagascar: Antsiranana Province, Diana Region, forest close to Ambohitra (formerly Joffreville) May 2005, 12°26´60˝S, 49°7´60˝E, 421 m asl, coll. R. Roy ( MNHN B 30154) . Paratypes: adult female (CW 37.8, CL 29.6, CH 15.5, FW 8.0), subadult female (CW 30.0, CL 23.6, CH 12.7, FW 6.6), northern Madagascar: Antsiranana Province, Réserve Spéciale d’Analamerana, Foret d’Ankavanana, 15.8 km southeast Anivorano-Nord , from partially disturbed mixed dry deciduous and humid forest, collected in early morning, 23 January 2004, 14°52´00˝S, 50°15´20˝E, 200 m asl, coll. S. M. Goodman ( FMNH 11045 ) ; adult male (CW 38.4, CL 28.8, CH 15.0, FW 8.3), adult female (CW 35.0, CL 28.0, CH 14.3, FW 8.1), Antsiranana Province, Réserve Spéciale d’Analamerana, Foret d’Ankavanana, 15.8 km southeast Anivorano-Nord , from partially disturbed mixed dry deciduous and humid forest, collected during night at edge of small stream at forest edge, 23 January 2004, 14°52´00˝S, 50°15´20˝E, 200 m asl, coll. S. M. Goodman ( FMNH 11046 ) ; adult male (CW 37.1, CL 29.2, CH 16.8, FW 8.1), Antsiranana Province, Réserve Spéciale d’Analamerana, Foret d’Ankavanana, 15.8 km southeast Anivorano- Nord , from partially disturbed mixed dry deciduous and humid forest, collected in late afternoon, 25 January 2004, 14°52´00˝S, 50°15´20˝E, 200 m asl, coll. S. M. Goodman ( FMNH 11050 ) ; adult female (CW 38.0, CL 28.7, CH 15.7, FW 8.5), adult male (CW 33.2, CL 26.2, CH 14.5, FW 7.5), Antsiranana Province, Réserve Spéciale d’Analamerana, Foret d’Ankavanana, 15.8 km southeast Anivorano-Nord , from partially disturbed mixed dry deciduous and humid forest, collected in the late afternoon, 25 January 2004, 14°52´00˝S, 50°15´20˝E, 200 m asl, coll. S. M. Goodman ( FMNH 11051 ) ; adult female (CW 39.1, CL 30.7, CH 17.1, FW 8.7) Antsiranana Province, Réserve Spéciale d’Analamerana, Foret d’Ankavanana, 15.8 km southeast Anivorano-Nord , from partially disturbed mixed dry deciduous and humid forest, collected at forest edge during night, 25 January 2004, 14°52´00˝S, 50°15´20˝E, 200 m asl, coll. S. M. Goodman ( FMNH 11052 ) ; adult female (CW 41.4, CL 31.9, CH 17.4, FW 8.7) Antsiranana Province, Réserve Spéciale d’Analamerana, Foret d’Ankavanana, 15.8 km southeast Anivorano-Nord , from partially disturbed mixed dry deciduous and humid forest, found on ground during day, 26 January 2004, 14°52´00˝S, 50°15´20˝E, 200 m asl, coll. S. M. Goodman ( FMNH 11054 ) ; adult female (CW 43.1, CL 34.2, CH 18.3, FW 9.9), Antsiranana Province, Réserve Spéciale d’Analamerana, Foret d’Ankavanana, 15.8 km southeast Anivorano-Nord , from partially disturbed mixed dry deciduous and humid forest, collected in late afternoon, 28 January 2004, 14°52´00˝S, 50°15´20˝E, 200 m asl, coll. S. M. Goodman ( FMNH 11056 ) ; juvenile male (CW 22.8, CL 17.6, CH 9.4,

FW 4.7) Antsiranana Province , Réserve Spéciale d’Analamerana , 8.6 km southeast Menagisy , Foret d’Analabe, along Bobakindro River, partially disturbed dry deciduous forest, collected early morning, 17 January 2004, 12°42´00˝S, 49°28´00˝E, 40 m asl, coll. S. M. Goodman ( FMNH 11060 ) ; adult male (CW 43.0, CL 31.6, CH 17.7, FW 11.6), Toamasina Province , Montagne d’Akirindro, 7.6 km, 17–21 March 2003, 15°17´00˝S, 49°32´34˝E, NNE Ambinantelo, 600 m asl, coll. P. Naskrecki ( NMU PN 17 – 21.3.2003) .

Diagnosis. Anterolateral margin lined by small granules. Suborbital, subhepatic, pterygostomial regions smooth with small field of granules at junction of longitudinal, vertical sutures. Outer face of merus of cheliped (pereiopod 1) smooth, granules present on upper margin only. Sternal sulcus s3/s4 complete, U-shaped, not meeting sterno-abdominal cavity. Terminal article of GO1 short, slim, tapered, with distinct raised rounded shoulder on external margin, slightly lower than junction with terminal article.

Description. Based on holotype, adult male. Carapace outline transversely oval, very high ( CH /FW 1.90); front narrow (FW/CW 0.22), deflexed; epibranchial tooth small, pointed, advanced in position, almost touching exorbital tooth; anterolateral margin evenly curved outward, lined by small granules, continuous with posterolateral margin, latter margin with faint or absent striae; postfrontal crest faint to absent, epigastric crests faint, positioned forward on front almost touching frontal margin, postorbital crests faint; deep mid-groove between epigastric crests forked posteriorly; cardiac, urogastric grooves faint, semicircular grooves deep; cervical grooves faint, long, not meeting postorbital crest. Suborbital region of carapace smooth, subhepatic region smooth, pterygostomial region smooth except for setae on lower margin, small field of granules at junction between longitudinal, vertical sutures; vertical sulcus on carapace sidewall curved, granular, running downward from base of epibranchial tooth to epimeral sulcus.

Epistomial tooth triangular, deflexed, edges smooth. Mandibular palp bilobed. Exopod of third maxilliped reaching to lower half of merus, exopod with short flagellum, ischium with deep vertical groove, curving distally toward medial margin. Sternal sulcus s1/s2 short, very faint; sternal sulcus s2/s3 completely crossing sternum; sternal sulcus s3/s4 with broad U-shaped groove, deep at edges, faint in middle; anterior sterno-abdominal cavity lacking setae. Sternal sulcus s4/s5 meeting abdomen at abdominal sulcus at a7/a6; sternal sulcus s6/s7 meeting a6 one half of segment length from a6/ a5. Episternal sulci s4/e4, s5/e5, s6/e6, s7/e7 absent, smooth.

Dactylus of both chelipeds relatively slender, approximately one-third height of palm, edges smooth except for 2 distinct teeth, one positioned basally, one half way along; upper margin of dactylus smooth; lower margin of propodus slightly indented. Fixed finger of propodus of major (right) cheliped slender with 3 large molars in proximal region (first 2 fused basally, third single) followed by series of small teeth. First carpal tooth on inner margin of carpus of cheliped large, pointed; second carpal tooth smaller, pointed, followed by a large granule. Medial, lateral margins of inferior face of merus of cheliped distinctly toothed, inferior face with pointed, granulated distal meral tooth; superior margin of merus of cheliped roughened by granules and short striae; outer face of merus smooth; granules on medial margin of merus, ischium of cheliped smooth, inferior margin of ischium rounded, smooth. Walking legs (p2-p5) elongated (ratio of merus length of p5 to CW 0.3), slender, inner margins of p2 to p5 propodi smooth. Male abdomen triangular, tapered distally, widest at a3, narrowest at a7 (telson); telson outline forming straightsided triangle with broad base, rounded apex.

Terminal article of GO1 short (ratio of length of terminal article to subterminal segment 0.25), slim, tapered, directed slightly outwards, straight, smooth, apical opening narrow; subterminal segment with junction between terminal article, subterminal segment not clearly visible on ventral side. Terminal article, subterminal segment separated on dorsal side by broad, trapezoid dorsal membrane; superior margin of dorsal membrane formed by diagonal basal margin of terminal article, inferior margin of membrane formed by diagonal J-shaped distal edge of subterminal segment; lateral margin of dorsal membrane broad, medial margin of membrane narrow, forming medial junction between subterminal segment, terminal article. Subterminal segments of GO1, GO2 subequal, but terminal article of GO2 much longer than terminal article of GO1. Terminal article of GO2 flagellum-like, about 2/3 length of subterminal segment, reaching anterior margin of sterno-abdominal cavity; tip of flagellum curving inward distally; distal parts of flagella of left, right GO2s crossing medially.

Comparisons. Foza ambohitra , sp. n., is assigned to the genus Foza on the basis of characters that it shares with F. raimundi Reed & Cumberlidge, 2006 , the typespecies of the genus ( Reed and Cumberlidge, 2006). Th e two species share a weak postfrontal crest, a narrow frontal margin of the carapace (FW/CW 0.22 F. ambohitra , 0.25 F. raimundi ) and a GO2 terminal article that curves inward distally; and the epibranchial tooth of both species is in a forward position, almost touching the exorbital tooth. Foza ambohitra can be distinguished from F. raimundi as follows: the terminal article of GO1 of F. ambohitra is cone-shaped and tapered ( Fig. 2A ), while that of F. raimundi is tube-shaped ( Reed and Cumberlidge, 2006: Fig. 2 B–D); both the superior part of the pterygostomial region and the sterno-abdominal cavity of F. ambohitra lack setae ( Fig. 1D , 2C), whereas setae are present in these regions in F. raimundi ; the anterolateral margin of F. ambohitra is granular and the posterolateral margin is smooth ( Fig. 1A ), whereas the anterolateral margin of F. raimundi is smooth and the posterolateral margin is carinated ( Reed and Cumberlidge, 2006: Fig. 1B ); and the major cheliped of F. ambohitra has three large molars ( Fig. 1E ) whereas that of F. raimundi has one large fused molar ( Reed and Cumberlidge, 2006: Fig. 1E ). Th e three species of Foza are compared in Table 1 . The differences between Foza and the other Malagasy freshwater crab genera are discussed by Reed and Cumberlidge (2006).

Etymology. Ambohitra is the modern name of Joffreville, a French colonial town in northern Madagascar, near where the specimens described here were collected. Ambohitra is a noun in apposition.

Distribution. Foza ambohitra is found in the Analamerana Mountains (12°44´00˝S, 49°36´00˝E), as well as the Ankavanana River (14°52´00˝S, 50°15´20˝E) and the Bobakindro River (12°42´00˝S, 49°28´00˝E) in Antsiranana Province in northeastern Madagascar.

Habitat. Partially disturbed mixed dry deciduous and humid forest in northern Madagascar.

Figures

Figure 1. Foza ambohitra sp. n. A carapace, frontal view B carapace, dorsal view C male abdomen D male sternum E major (right) cheliped F minor (left) cheliped G pereiopod 3 H pereiopod 5 I carpus and merus of major cheliped, dorsal view ł merus of major cheliped, ventral view K third maxilliped. Scale bar = 20 mm, A–ł; 7.5 mm, K.

Figure 2. Foza ambohitra sp. n. A dorsal view B frontal view C sternal view D major (right) cheliped. A, B adult female (FMNH 11056), CW 43.1 mm C, D holotype, adult male, CW 39.5 mm.

Figure 3. Foza ambohitra sp. n. A left GO1, ventral view B left GO1, dorsal view C left GO2, ventral view D terminal article of left GO1, close-up, ventral view E terminal article of left GO1, close-up, dorsal view. Holotype, adult male, length of the terminal article measured along the mid-line of the dorsal face from tip to dorsal membrane = 8.2 mm.