Foza Reed and Cumberlidge, 2006

Leever, Ellen M., Daniels, Savel R., Soma, Julia B. & Cumberlidge, Neil, 2022, Two new genera and a new species of freshwater crabs from northern Madagascar: Vahatra gen. nov. for Foza ambohitra Cumberlidge and Meyer, 2009, and Toamasina gen. nov. for Toamasina clarki sp. nov. (Brachyura: Potamoidea: Deckeniidae), Journal of Natural History 56 (1 - 4), pp. 241-263 : 258-261

Foza Reed and Cumberlidge, 2006

( Figure 7 (a–l); Tables 1–4 )

Foza Reed and Cumberlidge, 2006: 59–60 , figs 1, 2.

Foza – Cumberlidge and Meyer 2009:78 (name only) (not Foza Reed and Cumberlidge,2006 ). Foza – Cumberlidge et al. 2015: 3 (partim).

Foza – Cumberlidge et al. 2020: 586 (name only).

Foza – Cumberlidge et al. 2021: 5 (name only) (partim).

Type species

Foza raimundi Reed and Cumberlidge, 2006 , by original designation.

Rediagnosis

Carapace front conspicuously narrow (FW/CW = 0.24–0.25), sharply deflexed; carapace extremely high ( CH /FW = 0.48) ( Figure 7 (b)); lateral margin of carapace curved evenly outward, lined with small granules, continuous with posterolateral margin; postfrontal crest faint to absent, postorbital crests lacking, epigastric crests faint, positioned forward on front almost touching frontal margin; deep mid-groove between epigastric crests forked posteriorly; distinct notch between the exorbital, epibranchial teeth ( Figure 7 (a)); branchiostegite pterygostomial region with broad area of dense setae, suborbital, subhepatic regions smooth (except for carinae near posterolateral margin) ( Figure 7 (b)); eyestalks, cornea, normal size ( Figure 7 (b)); mandibular palp terminal article bilobed, anterior lobe on terminal article conspicuous, large-sized (MPAL/MPTA = 0.6) ( Table 2 ); exopod of third maxilliped reaching lower half of merus; exopod with short flagellum (less than, or equal to, merus length); ischium with faint vertical sulcus curving distally towards medial margin ( Figure 7 (b)); ambulatory legs (P2–5) long (ΣP2–5/ CW = 7.3) Table 3 ); anterior sterno-pleonal cavity lined with short setae; sternal sulcus S1/2 short, very faint; S2/3 completely crossing sternum; S3/4 V-shaped, deepest at edges, faint in middle; episternal sulci S4/E4, S5/E5, S6/E6, S7/E7 absent, smooth; S4/5 meeting PL6/telson; S6/7 meeting PL6 one-quarter of segment length from PL6/5 ( Figure 7 (c)); male pleon slim, triangular, tapered, widest at PL3; telson outline forming straight-sided triangle with broad base, rounded apex ( Figure 7 (c)); G1 TA short (G1 TA/ SA = 0.25), straight, broadly conical, tip wide ( Figure 7 (g)); G2 TA extremely long (length G2 TA either subequal, or greater than G2 SA), G2 TA tip with distinct distal curve ( Figure 7 (i)).

Distribution

The revision of Foza restricts its distributional range to three locations, all in the Antsiranana Province in northern Madagascar: two in the Diana Region (the Montagne des Francais Reserve and the Ankarana Special Reserve), and one in the Sava Region ( Marojejy National Park). The humid forested slopes of Mount Marojejy in the Marojejy National Park are the most northerly extent of the continuous eastern rainforests in Madagascar, while the other two localities are in dry deciduous and riverine forest that is part of a limestone plateau with tsingy and numerous caves and canyons. The range of the revised Foza does not now include any localities farther south than this (e.g. in Toamasina Province) ( Figure 6 ).

Species included

Foza raimundi Reed and Cumberlidge, 2006 and Foza manonae Cumberlidge, Klaus, Meyer, and Koppin, 2015 .

Remarks

The removal from Foza of A. goudoti (by Cumberlidge et al. 2020) and V. ambohitra (present work) leaves this genus with two species, F. raimundi and F. manonae . The revised genus diagnosis provided here distinguishes Foza from the other Malagasy freshwater crab genera.

Foza manonae sp. nov. was assigned to Foza on the basis of characters that it shares with F. raimundi . These include a conspicuously bilobed mandibular palp ( Cumberlidge et al. 2015, fig. 2e,f), a faint postfrontal crest ( Cumberlidge et al. 2015, fig. 1a,b), a sternal groove S6/7 that meets the margin of PL 5 in the middle of the article ( Cumberlidge et al. 2015, fig. 2d), and a curved, elongated G2 TA that is curved inward distally ( Cumberlidge et al. 2015, fig. 2a). Molecular evidence that may guide the decision to continue to group F. manonae in the same genus as F. raimundi is not currently available (except for a preliminary, unpublished DNA comparison of 16S rRNA sequences of F. manonae with other Malagasy freshwater crab taxa that placed it in a separate clade from F. raimundi ).

For the time being, F. manonae is retained in Foza , but we are aware of a number of characters of the carapace, thoracic sternum and gonopods ( Figure 7 (d–f,j–l)) that distinguish it from F. raimundi ( Figure 7 (a–c,g–i)), the type species of the genus ( Reed and Cumberlidge 2006). For example, the G1 TA is short and slender, and glabrous on the dorsal side, in F. manonae ( Figure 7 (k)), vs short and stout, and heavily setose on the dorsal side, in F. raimundi ( Figure 7 (h)); the S3/4 is glabrous, incomplete, and only visible as two short lateral depressions in F. manonae ( Figure 7 (f)), vs a heavily setose and complete S3/4 that traverses the thoracic sternum in F. raimundi ( Figure 7 (c)); the carapace lateral margin is strongly convex in F. manonae ( Figure 7 (d)), vs a weakly convex carapace lateral margin in F. raimundi ( Figure 7 (a)); the ambulatory legs (P2–5) are short (ΣP2–5/CW = 4.7) in F. manonae ( Table 3 ), v ersus ambulatory legs (P2–5) that are long (ΣP2–5/CW = 7.3) in F. raimundi ( Table 3 ); and the telson has gently sinuous lateral margins in F. manonae ( Figure 7 (c)), vs a telson with straight lateral margins ( Figure 7 (f)).

Figures

Figure 6. Map of Madagascar showing the distributional range of Vahatra ambohitra (Cumberlidge and Meyer, 2009) comb. nov. (black circles, not shown to scale), Toamasina clarki sp. nov. (white triangle in black square, not shown to scale), Foza raimundi Reed and Cumberlidge, 2006 (white asterisk with black margin), and Foza manonae Cumberlidge, Klaus, Meyer, and Koppin, 2015 (white square with black margin). Scale bar = 184 km.

Figure 7. Foza raimundi Reed and Cumberlidge, 2006, adult ♂, CW 18.7 mm, FMNH 15336, from Marojejy National Park, Madagascar: a, dorsal view of cephalothorax; b, frontal view of cephalothorax; c, ventral view of cephalothorax; g, ventral view of left G1; h, dorsal view of left G1; i, ventral view of left G2. Foza manonae Cumberlidge, Klaus, Meyer, and Koppin, 2015, holotype, adult ♂, CW 43.07 mm, ZSM A20145003, from Ankarana Special Reserve, Madagascar: d, dorsal view of cephalothorax; e, frontal view of cephalothorax; f, ventral view of cephalothorax; j, ventral view of left G1; k, dorsal view of left G1; l, ventral view of left G2. Scale bar:a–c = 6.6 mm; d–f = 10.0 mm; g, h = 2.0 mm; i = 2.5 mm; j, k = 3.3 mm; l = 4.0 mm.