Boophis sandrae, Glaw & Köhler & Riva & Vieites & Vences, 2010

Glaw, Frank, Köhler, Jörn, Riva, Ignacio De La, Vieites, David R. & Vences, Miguel, 2010, Integrative taxonomy of Malagasy treefrogs: combination of molecular genetics, bioacoustics and comparative morphology reveals twelve additional species of Boophis 2383, Zootaxa 2383 (1), pp. 1-82 : 40-45

Boophis sandrae sp. nov.

( Fig. 19 , Appendix 9)

Remark. Not surprisingly, due to their external similarity, largely similar call structure, and sympatric occurrence, Boophis elenae and B. sandrae have long been confused. In the original description of B. elenae, Andreone (1993) shows photographs of the holotype specimen (MRSN A69) in life, leaving no doubt about its identity due to the clearly visible reddish horizontal stripes in the iris which are absent in B. sandrae . Andreone (1993) mentions this iris character and attributes a further specimen (female paratype MRSN A71.2 from Ambatolahy) without iris stripes to B. elenae as well. Considering the new classification proposed herein, this specimen belongs instead to B. sandrae . Specimens of B. sandrae have been reported as " B. sp. aff. elenae " by Vences et al. (2006) and by Glaw & Vences (2007:168–169), and as Boophis sp. 22 in Vieites et al. (2009). See also section on Available names in the description of Boophis luciae below.

Holotype. ZMA 20133 ( ZCMV 352 ), adult male, from Ranomafana , Andranoroa river , near Ranomafanakely, 21°14.872'S, 47°22.580'E, 1138 m a.s.l., southeastern Madagascar, collected on 29 January 2004 by I. De la Riva, D. R. Vieites and M. Vences.

Paratypes. ZFMK 62311–62312 , male and female respectively, from Ranomafana village , 21°15.699'S, 47°27.571'E, 619 m a.s.l., collected on 5 March 1996 by F. Glaw, D. Rakotomalala and F. Ranaivojaona ; ZMA 20132 ( ZCMV 327 ), female, from Ranomafana , Andranoroa river near Ranomafanakely, 21° 14.872' S, 47° 22.580' E, 1138 m a.s.l., collected on 28 January 2004 by I. De la Riva and M. Vences ; ZMA 19389 ( FGMV 2002.447 ) from Ranomafana village (Hotel Manja), collected on 23 January 2003 by F. Glaw, M. Puente, L. Raharivololoniaina, M. Thomas and D . R. Vieites ; ZMA 20134–20135 ( ZCMV 585–586 ), two males, from Ranomafana village , 21°15.699' S, 47°27.571' E, 619 m a.s.l., collected on 5 February 2004 by N. Fatroandrianjafinonjasolomiovazo ; ZMA 20136 ( ZCMV 631 ), male, from Ambatolahy forest , 21°14.632'S, 47°25.573'E, 915 m a.s.l., collected on 10 February 2004 by D . R. Vieites and C. Woodhead ; ZMA 20137 ( ZCMV 634 ), male, from the surroundings of Ranomafana National Park (probably from the village of Ranomafana; no further data available) ; ZSM 235 /2006 ( ZCMV 3003 ), male, from Ambatovory (upstream river Ambatolahy), 21°14.279' S, 47°25.487' E, 966 m a.s.l., collected on 26 February 2006 by P. Bora, Y. Chiari , T. Rajaofiarison, E. Rajeriarison , T. Razafindrabe and M. Vences ; ZSM 236 /2006 ( ZCMV 3058 ), female, from Ambatolahy river , 21°14.632' S, 47°25.573' E, 915 m a.s.l., collected on 26 February 2006 by P. Bora, Y. Chiari , T. Rajaofiarison, E. Rajeriarison , T. Razafindrabe and M. Vences ; ZSM 237 /2006 ( ZCMV 3187 ), male, from Kidanavo bridge, 21°13.571' S, 47°22.176' E, 1152 m a.s.l., collected on 20 February 2006 by A. Meyer, L. du Preez, O. Verneau, D . R. Vieites and C. Weldon ; ZSM 238 /2006 ( ZCMV 3371 ), female, from Mahakajy , collected on 1 March 2006 by T. Rajaofiarison, E. Rajeriarison and M. Vences ; ZSM 665 /2003 ( FGMV 2002–0245 ), adult male, from point between Vohiparara and entrance to Ranomafana National Park, collected on 16 January 2003 by F. Glaw, M. Puente, L. Raharivololoniaina, M. Thomas and D . R. Vieites .

Etymology. This species is dedicated to Sandra Nieto Román, in recognition for her patience, interest and help during the field work and nights spent in the laboratory, by her husband, David R. Vieites.

Diagnosis. Assigned to the genus Boophis based on the presence of an intercalary element between ultimate and penultimate phalanges of fingers and toes (verified by external examination), presence of nuptial pads and axillary amplexus and absence of femoral glands in males, absence of gular glands in males, enlarged terminal discs of fingers and toes, lateral metatarsalia separated by webbing, absence of outer metatarsal tubercle, molecular phylogenetic relationships (see Vieites et al. 2009 for a complete molecular analysis of Boophis ), and overall similarity to other Boophis species. Assigned to the Boophis luteus group based on the following combination of characters: moderate size (male SVL 36–48 mm); absence of tubercles or flaps on heel and elbow; presence of webbing between fingers; indistinct canthus rostralis; presence of distinct white tarsal folds; dorsal colouration translucent green in life and yellow-whitish in preservative; absence of red ventral colour; ventral skin in life non-transparent; bilobed subgular vocal sac; presence of vomerine teeth; and molecular phylogenetic relationships. Boophis sandrae differs from all other species in the Boophis luteus group by strong genetic differentiation (see below) and by advertisement calls: in brief, the general call structure consisting of a long rapid series of short and unharmonious notes observed in B. sandrae is known from only in three other species in the group ( B. andreonei , B. anjanaharibeensis , B. elenae ), whereas other species have series of melodious whistling notes ( B. englaenderi , B. luteus , B. septentrionalis , B. tampoka ) or slow series of pulsed notes ( B. andohahela , B. jaegeri ); in calls of B. elenae , note repetition rate is lower and notes longer, and in B. anjanaharibeensis , call repetition rate is higher and notes shorter (see Comparative call data below); no obvious call differences exist to B. andreonei which however is a smaller species (SVL 31–33 mm vs. 36–48 mm in B. sandrae ) without an obvious dorsal pattern of darker green spotting (vs. presence). Boophis sandrae differs from B. luteus , B. anjanaharibeensis , and the morphologically most similar species, B. elenae , by its iris colouration (without red vs. with thin red horizontal stripes or a broad ring of red colour). It further differs from B. andohahela , B. septentrionalis and B. tampoka by the absence of light yellowish dorsolateral lines (versus presence).

Description of the holotype. Adult male, SVL 35.8 mm. Body slender; head slightly longer than wide, wider than body; snout rounded in dorsal view, obtuse in lateral view, nostrils directed laterally, slightly nearer to eye than to tip of snout; canthus rostralis sharp in cross section, straight in dorsal view, loreal region slightly concave; tympanum distinct, rounded, TD 36% of ED; supratympanic fold indistinct; vomerine odontophores distinct, well separated in two round patches, positioned posteromedial to choanae; choanae medium-sized, rounded. Tongue bifid, free posteriorly. Arms slender, subarticular tubercles single, round; metacarpal tubercles not recognizable; fingers moderately webbed and with lateral dermal fringes; webbing formula 1(-), 2i(1), 2e(1), 3i(2), 3e(1), 4(1); relative length of fingers 1<2<4<3 (finger 2 distinctly shorter than finger 4); finger discs moderately enlarged; distinct, well developed nuptial pad on inner side of first finger, unpigmented. Hindlimbs slender; tibiotarsal articulation reaching nostril when hindlimb is adpressed along body; lateral metatarsalia separated by webbing; inner metatarsal tubercle small, distinct, elongated; no outer metatarsal tubercle; webbing between toes well-developed, lateral dermal fringes present; webbing formula 1(0), 2i(0.25), 2e(0), 3i(1), 3e(0), 4i(1), 4e(1), 5(0); relative length of toes 1<2<5=3<4; toe discs enlarged. Skin on dorsal surfaces smooth, very finely granular on throat, coarsely granular on chest and belly; a glandular area ventrally under the cloacal opening; no distinctly enlarged tubercles in the cloacal region. A tissue sample was removed from the right thigh.

Measurements (in mm): SVL 35.8, HW 12.1, HL 12.9, ED 5.5, END 2.4, NSD 3.3, NND 4.3, TD 2.0, TL 18.9, HAL 10.2, FOL 15.7, FOTL 25.7.

After almost four years in preservative, ground colour of flanks, dorsal and ventral surfaces uniformly creamy yellow. Skin above eye blackish. Nostril internally bordered with some dark pigment.

In life, ground colour of upper surface of head and dorsum light green with darker green spotting. A pale grey stripe at midflanks with dark green reticulations, below this stripe unpigmented. A bluish shade present on external edge of upper eyelid, loreal region, upper lip, tympanic region and borders of the concealed parts of the hindlimbs. Posterior iris periphery black, followed by light blue. Eye periphery black posteriorly ( Fig. 19 ). White lateral fringes along lateral edge of lower arm, tarsus, and heel. Webbing yellowish green. Small, distinct white spots scattered on posterior part of head, back and hindlimbs. Dorsal surfaces of fingers and toes green, terminal discs green. Ventral life colouration of holotype unknown.

Variation. Morphological variation is given in Appendix 6. Females are larger, with an average of 144 % of male SVL. The paratypes are similar to the holotype. The dorsal colouration of the female paratype ZSM 236 /2006 is more yellowish, especially on the flanks, and with three distinct yellow spots between the eyes. The forelimbs and hindlimbs are more brownish, with distinct light bands. The ventral surfaces of limbs are translucent bluish green, and the chest and belly translucent pinky white. Bones bluish green. Iris pale pink. In calling males we observed a bilobed subgular vocal sac .

Natural history. This species is common in the Ranomafana region. Its typical calls can be heard in dense rainforest but also very commonly in degraded or secondary forest and, in largely cleared areas, from large trees along streams and rivers. Calling specimens usually are perched quite high, often 2–4 m above the ground, and usually sit on thin branches rather than on leaves. In the later evening, pairs in axillary amplexus can be observed at lower heights in the vegetation along the streams. The species is often found in close syntopy with B. luteus but has not been recorded in the same stretch of stream with the externally similar B. elenae .

Vocalization. The call of Boophis sandrae consists of a very long series of short pulsed notes repeated in very fast succession. One such call (note series) recorded on 28 January 2004 near Vohiparara, Ranomafana National Park, had a duration of 33.6 seconds ( Fig. 20A ). Each note is distinctly pulsed and composed of 3–7 (4.7 ± 0.96; n = 30) pulses, which increase in amplitude towards the end of the note. Numerical call parameters are as follows: note duration, 13–23 ms (18.9 ± 2.4; n = 15); inter-note intervals, 35–43 ms (37.5 ± 2.6; n = 17); note repetition rate, 22 notes/second; dominant frequency range 2200–3500 Hz, maximum call energy at 2870–2970 Hz ( Vences et al. 2006; CD 1, track 24). Another call series of 45 seconds duration recorded near Ranomafana on 1 March 1996 (at 22°C) exhibits the following parameters: note duration, 27–34 ms (30 ± 2; n = 11); inter-note intervals, 14–18 ms (16 ± 1; n = 10); note repetition rate, 22 notes/second; dominant frequency range 2150–3600 Hz, maximum call energy at 3000–3200 Hz. Although there are slight differences in the measurements of note duration and inter-note intervals, the general character of both calls recorded is nearly identical and leaves no doubt that both belong to the same species. Differences are most probably due to different recording qualities (poor quality in the second mentioned recording).

Comparative call data. The sister species of B. sandrae , B. anjanaharibeensis , also emits long series of very short notes in rapid succession. In 2005, we were able to observe several specimens of this species emitting the call at Marojejy National Park, and our assignment of these call data to the species is thus reliable. In contrast, the calls tentatively assigned to the species by Andreone (1996) probably do not belong to this species (specimens were not observed calling by the author). These calls have a note repetition rate of 5.1 notes/ second only, in contrast to approximately 40 notes/second observed by us in 2005. Compared to B. sandrae , note duration in B. anjanaharibeensis is much shorter (2–5 vs. 13–34 ms) and note repetition rate is much faster (40 vs. 22 notes/second), whereas maximum call energy is distributed roughly in the same frequency band (2950–3150 Hz) and inter-note intervals (18–27 ms) are also similar to B. sandrae (recording of B. anjanaharibeensis obtained at Marojejy National Park; Vences et al. 2006, CD 1, track 18). Also, calls of B. elenae consist of a long series of short pulsed notes, repeated in fast succession ( Fig. 20B ). However, note duration is longer and repetition rate significantly lower when compared to calls of B. sandrae . For detailed comparison, we here provide numerical parameters of the call of B. elenae recorded at Maharira forest (air temperature 18.4°C): duration of call series, 8877 ms; note duration, 78–110 ms (94 ± 9; n = 24); inter-note interval, 50–86 ms (66 ± 8; n = 24); note repetition rate, 6.1–6.4 notes/second; dominant frequency range 1900–2900 Hz, maximum call energy at 2510–2705 Hz ( Vences et al. 2006, CD 1, track 19).

Molecular relationships. The phylogenetic tree of species in the Boophis luteus group ( Fig. 18 ) shows a poor basal resolution, but some relationships among species are well resolved. As already indicated by a similar analysis (with fewer sequences of similar length; Köhler et al. 2007), Boophis tampoka is resolved sister to B. luteus (BS 97%, BPP significant), and B. englaenderi seems to be related to these (albeit without bootstrap or Bayesian support). Boophis elenae is grouped with B. andreonei and B. jaegeri (not supported by bootstrap or Bayesian support values), while the sympatric B. sandrae groups with B. anjanaharibeensis (BP 97%, BPP significant), and the sandrae / anjanaharibeensis lineage appears to be related to B. septentrionalis (no bootstrap or Bayesian support). Boophis sandrae (only topotypical specimens from the Ranomafana region considered) shows high genetic divergences to B. anjanaharibeensis (5.2–6.1%) and to all other representatives of the group (>7%). Interestingly, putative specimens of B. sandrae from Andasibe are genetically also quite divergent (2.8–5.0%) to topotypical specimens, and also comprise two sympatric lineages differentiated by 2.3% among each other. Because these sequences are based on tadpole specimens only ( Raharivololoniaina et al. 2006) the identity of this population cannot be further investigated here, but most probably they represent at least one further undescribed species.

Distribution. The distribution of B. sandrae encompasses various sites, all in the region around Ranomafana National Park, including Ambatolahy, Vohiparara, and Ranomafana village (Appendix 10). Similar specimens have been photographed and collected in the region around Andasibe, but based on tadpole sequences in Fig. 18 these specimens are strongly differentiated and may belong to another species.

Figures

FIGURE 18. Maximum parsimony 16S rRNA phylogram for species in the Boophis luteus group. From 470 total characters, 347 were constant and 111 parsimony informative. MP searches retained 60 trees of which a strict consensus is shown. Consensus support values higher than 50, from 2000 bootstrap replicates, are shown; an asterisk indicates Bayesian posterior probabilities equal or higher than 95%. The species newly described herein is in bold.

FIGURE 19. (A) Male holotype of Boophis sandrae sp. nov. (ZMA 20133) from Ranomafana; (B) female paratype of Boophis sandrae sp. nov. (ZSM 236/2006) from Ambatolahy.

FIGURE 20. Spectrograms and waveforms of advertisement calls: (A) section of advertisement call of Boophis sandrae sp. nov. from near Vohiparara, Ranomafana National Park (recorded on 28 January 2004, air temperature 20–21°C); (B) advertisement call of Boophis elenae from Maharira Forest, Ranomafana National Park (recorded on 24 January 2004, air temperature app. 18.4°C).