Mantidactylus

Knoll, Angelika, Köhler, Jörn, Glaw, Frank, Teschke, Meike & Vences, Miguel, 2007, Larval morphology in four species of Madagascan frogs of the subgenus Brygoomantis (Mantellidae: Mantidactylus), Zootaxa 1616, pp. 49-59 : 54-57

Mantidactylus sp. aff. betsileanus "Vohidrazana"

Series examined. ZSM 1042/2004 (3 specimens), 1043/2004 (3 specimens) and 1063/2004 (1 specimen), all from the forest of An’Ala. Two of the tadpole series were collected in a quiet running brook of about two meters in diameter and 30 to 70 cm depth. The stream bed was sandy. The third series was sampled from a shallow system of connected puddles containing dead leaves which covered the ground.

Taxonomic note. This is a further sibling species of M. betsileanus of which so far no adult morphological or bioacoustic data have become available. The known DNA sequence of this species is from the locality Vohidrazana, and the tadpoles from the nearby site An'Ala indicate that this species may be widespread at mid to low elevations of central eastern Madagascar.

Description (based on tadpole ZSM 1063/2004, field number 2003.2015; Genbank accession number EF606886 ; Fig. 3 ). Tadpole in stage 37 and in a fairly good state of preservation. Colouration in preservative is transparent tan with a yellowish shade. Dorsum uniformly transparent yellowish, above each external nare an orange coloured spot visible through the transparent skin, not visible in ventral view. Dorsal fin, belly and ventral caudal fin lacking darker flecks. In dorsal view, body shape elliptical. In lateral view, body very depressed, BW 1.41 of BH. Body shape in lateral view flattening toward snout. Nostrils directed dorsolaterally, round, not protuberant, positioned closer to the tip of the snout than to the eyes, S– N 0.83 of N–E. Eyes positioned dorsally, oriented dorsolaterally, moderately sized, ED 0.08 of BL, not visible in ventral view. Snout rounded in lateral view, nearly rounded in dorsal view. Spiracle sinistral, closely attached to the body wall, visible in dorsal view. Spiracular opening oval, upper margin situated approximately at level of lower margin of eye, slightly closer to the end of the body than to the tip of the snout, S– S 0.58 of BL. Intestinal spiral well visible in lateral and ventral view, also visible in dorsal view. Short, flattened vent tube, almost median, cloacal opening dextral to caudal fin, attached directly to the ventral fin. Caudal musculature well developed, upper origin well visible in dorsal view, TMH 0.63 of BH and 0.59 of MTH. Dorsal fin originating on base of caudal musculature, increasing in height at proximal third of tail, MTH 1.07 of BH, maintaining equal height throughout two-third of the tail, slightly diminishing to finely rounded tip. Dorsal fin slightly convex in outline, ventral fin almost straight, equally sized, margins nearly parallel with the margins of the tail muscle. Oral disc small, generalized, ODW 0.22 of BL and 0.40 of BW, transversely elliptical, directed anterioventrally, laterally emarginated, not visible in dorsal view, but margins visible in lateral view. All but its anterior margin free from the body wall. Large dorsal gap, DG 0.74 of ODW, upper labium with 8 marginal papillae and one submarginal papilla on each side. Lower labium with two continuous rows of papillae (app. 46 in marginal row). All papillae with a rounded tip, cores pigmented, less than 1.0 mm in length each. Keratodont row formula 1:4+4/3, about 60 keratodonts per mm. Keratodont row length reduces from A2 to A5, large medial gap in second anterior keratodont row. Beak well-developed and dark brown, both jaw sheaths with serrations at their cutting edges. Upper beak M-shaped, lower beak V-shaped.

Measurements (in mm). BL 10.3; TAL 19.8; TL 30.4; BW 5.8; BH 4.1; ED 0.9; IOD 3.1; IND 2.0; S– N 1.5; N– E 1.8; S– S 6.1; TMH 2.6; TMW 2.4; MTH 4.4; ODW 2.3; DG 1.7.

Variation within the series. The series ZSM 1043/2004 and ZSM 1042/2004 contain three additional undamaged tadpoles at stages 26, 37 and 40, respectively. TL ranges from 26.3 mm (stage 26) to 32.9 mm (stage 40), and BL from 8.6 mm (stage 26) to 10.8 mm (stage 40). The proportions vary as follows: BW 1.19– 1.42 of BH, ED 0.08–0.10 of BL, S– N 0.75 –0.84 of N–E, IND 0.60–0.79 of IOD, S– S 0.56 –0.63 of BL, TMH 0.65–0.87 of BH, TMH 0.60–0.75 of MTH, MTH 0.92–1.16 of BH, ODW 0.23–0.24 of BL, ODW 0.40–0.48 of BW (see Tab. 3 ). Keratodont row formula is homogenous within the sample, as are general morphology and colouration.

Previous descriptions. See discussion.

Specimen examined. ZSM 879/2004 (1 specimen) from Fierenana. The tadpole was collected in a puddle beside a footpath on a muddy ground. Collection was done in February 2003.

Taxonomic note. Based on the original description and on our own examination of the types (M. Vences, unpublished), the defining character of M. biporus are two separated rudimentary clusters of femoral glands in females. Furthermore, the type specimens of M. biporus exhibit larger body sizes than many other populations assigned to M. biporus . Based on these observations, the population from Fierenana (with double glands in females and relatively large body sizes) qualifies as representing this species more closely than any of the populations listed by Vences et al. (2006) as M. sp. aff. biporus .

Description (based on a single tadpole, ZSM 879/2004, field number 2003.1667; Genbank accession number EF606883 ; Fig. 4 ). Tadpole in stage 37 (no other conspecific larvae were found) and fairly good state of preservation (bit from the dorsal tail fin has been excised for DNA analysis). The colouration of the preserved tadpole is pale brown to tan with a yellowish shade. Dorsum scattered with slightly darker irregular flecking, as dorsal fin, especially on the body-tail junction; belly and ventral caudal fin transparent yellowish, almost lacking darker flecks. In dorsal view, body shape elliptical. In lateral view, body depressed, BW 1.72 of BH. Body shape in lateral view flattening toward snout. Nostrils directed dorsolaterally, round, not protuberant, positioned closer to the eyes than to the tip of the snout, S– N 1.25 of N–E. Eyes positioned dorsally, oriented dorsolaterally, moderately sized, not visible in ventral view, ED 0.09 of BL. Snout rounded in lateral view, nearly rounded in dorsal view. Spiracle sinistral, closely attached to the body wall, not visible in dorsal view. Spiracular opening oval, upper margin situated approximately at level of lower margin of eye, closer to the end of the body than to the tip of the snout, S– S 0.61 of BL. Intestinal spiral slightly visible in lateral view and well visible in ventral view. Short, flattened vent tube, almost median, cloacal opening dextral to caudal fin, attached to the ventral fin. Caudal musculature well developed, TMH 0.74 of BH and 0.62 of MTH, gradually tapering from base to not clearly visible pointed tip. Dorsal fin originating on base of caudal musculature, as far as noticeable due to the excision, increasing in height at the end of the proximal third of tail, MTH 1.19 of BH, maintaining equal height throughout two-third of the tail, slightly diminishing to finely rounded tip. Dorsal and ventral fin slightly convex in outline, equally sized, margins nearly parallel with the margins of the tail muscle. Oral disc small, generalized, ODW 0.21 of BL and 0.33 of BW, transversely elliptical, directed anterioventrally, laterally emarginated, not visible in dorsal view, but margins visible in lateral view. All but its anterior margin free from the body wall. Large dorsal gap, DG 0.69 of ODW, upper labium with 8 marginal papillae and 4 submarginal papillae on each side. Lower labium with two rows of papillae (app. 34 in marginal row, app. 26 in submarginal row). All papillae with a rounded tip, cores of papillae are pigmented, less than 1.0 mm in length each. Keratodont row formula 1:3+3/1+1:2, about 50 keratodonts per mm. Keratodont row length reduces from A2 to A4, large medial gap in second anterior keratodont row. First posterior row with small medial gap and app. 1.5 times larger keratodonts. Beak well developed and black, both jaw sheaths with serrations at their cutting edges. Upper beak M-shaped, lower beak V-shaped.

Measurements (in mm). BL 15.2; TAL 32.1; TL 47.3; BW 9.8; BH 5.7; ED 1.3; IOD 4.5; IND 2.6; S– N 2.0; N– E 1.6; S– S 9.3; TMH 4.2; TMW 4.3; MTH 6.8; ODW 3.2; DG, 2.2.

Previous descriptions. None.

Figures

FIGURE 3. Drawings of the preserved voucher tadpole of Mantidactylus sp. aff. betsileanus " Vohidrazana " (stage 37), series ZSM 1063 / 2004 (left leg cut for tissue sample); (A) dorsal view, (B) lateral view, (C) oral disc.

FIGURE 4. Drawings of the preserved voucher tadpole of Mantidactylus biporus (stage 37), series ZSM 879 / 2004 (part of dorsal fin cut for tissue sample); (A) dorsal view, (B) lateral view, (C) oral disc.

Tables

TABLE 3. Variation in measurements, body proportions and keratodont row formulae of Mantidactylus sp. aff. betsileanus " Vohidrazana " (undamaged specimens from series ZSM 1042 / 2004, 1043 / 2004, 1063 / 2004). All measurements in millimeters. Each column represents measurements from a single specimen.

ZSM 1063/2004	1042/2004	1042/2004	1043/2004
Stage 37	37	40	26
BL 10.6	10.6	10.8	8.6
TAL 19.8	22.3	22.1	17.7
TL 30.4	32.9	32.9	26.3
Keratodont row formula 1:4+4/3	1:4+4/3	1:4+4/3	1:4+4/3
TAL/ BL. 1. 9	2. 1	2.0	2.1
Mantidactylus biporus (Boulenger, 1889)