Natural history and larval morphology of Boophis occidentalis (Anura: Mantellidae: Boophinae) provide new insights into the phylogeny and adaptive radiation of endemic Malagasy frogs

Abstract

During a zoological survey in north-west Madagascar (Sahamalaza Peninsula) we documented aspects of the natural history of Boophis occidentalis (formerly a subspecies of B. albilabris and here raised to species level). Individual age assessed by skeletochronology ranged from 4 to 11 years. Breeding behaviour was observed at a seasonal stream after heavy rainfalls: ®ve choruses of eight to 90 males aggregated in shallow brook sections. The males emitted low frequency calls and engaged in scramble battles. Only two females were found. A couple laid a large number of eggs, attached as a single layer on submerged stones. Tadpoles reared from these eggs had the typical morphology of brook-breeding Boophis species with a 1:5+5/3 keratodont formula and a relatively¯attened body. Adult males had an anteroventrally oriented cloaca, a morphological trait shared with B. albilabris. Advertisement calls were similar in general structure to those of B. albilabris recorded at Anjanaharibe-Sud. They were unharmonious and consisted of pulsed notes emitted at irregular intervals. Much lower pulse rates in B. albilabris (30±38 pulses/s) than in B. occidentalis (90±109 pulses/s) support the speci®c distinctness of these taxa. The combination of characters related to reproductive biology in B. occidentalis and B. albilabris is unique in Boophis. The acontinuous breeding behaviour and large number of eggs per clutch are traits found in the pond-breeding species of the B. tephraeomystax group, while larval morphology and habitat are characteristic of brook-breeding species. Available morphological and molecular data place B. albilabris and B. occidentalis into the brookbreeding Boophis radiation. The acontinuous timing of reproduction and large egg number may be secondary adaptations that allowed the species to colonize arid regions of western Madagascar.

Molecular identification, description, and phylogenetic implications of the tadpoles of 11 species of Malagasy treefrogs, genusBoophis

“…Our data, in combination with published tadpole descriptions of other Boophis species (Blommers-Schlö sser 1979b; Vences 1992, 1994;Andreone et al 2002; Tadpoles of the genus Boophis 1475 Grosjean et al 2006), provide evidence for varying degrees of larval adaptation to running water in the stream-breeding clade of this genus. In the field we observed many times how species with large oral discs and strong caudal musculature were mainly distributed in fastflowing parts of streams, and how these tadpoles attached to the surface of rocks and, later, of collecting bags or buckets with their oral discs.…”

“…Based on the large size of juveniles, which already bear characters of the morphology of the adults, we also consider the B. goudoti tadpoles described by Blommers-Schlö sser (1979b) as likely to be correctly identified. The tadpole of B. occidentalis, described by Andreone et al (2002), was reared from eggs deposited by a large aggregation of breeding adults, and its identification is therefore beyond doubt. The tadpole of B. jaegeri as described by Glaw and Vences (1994) was collected at the type locality of this species, Nosy Be, where only one additional stream-breeding Boophis occurs (B. brachychir).…”

Giant and long-lived? Age structure in Macroscincus coctei, an extinct skink from Cape Verde

“…In amphibians and reptiles living in the temperate regions, each LAG corresponds to an arrested osteogenesis during the autumn-winter cessation of growth. Alternatively, in tropical species the presence of bone growth marks may depend more on factors other than temperature, such as rain-dryness alternations, or food availability (e.g., Zug and Rand, 1987;Guarino et al, 1998;Andreone et al, 2002).…”

A new frog of the genus Mantidactylus from the rainforests of north-eastern Madagascar, and its karyological affinities

“…As it has been stressed in a recent paper (Vences et al, 2002), it is likely that the genus is paraphyletic, and it will be necessary, sooner or later, to elevate to generic rank some of its subgenera. Despite the incompletetaxonomicknowledge,it is clear that within Madagascar there are hotspots for speci c diversity and endemism of different Mantidactylus groups.…”

“…In some recent papers Vences, 2000a, 2001;Vences and Glaw, 2001;Vences et al, 1997Vences et al, , 2002 available material of two subgroups of the mantellid genus Mantidactylus (Dubois, 1992;Andreone, in press) was analysed and partially revised: Gephyromantis and Phylacomantis. These subgenera include (beside a third subgenus, Laurentomantis) the Mantidactylus representatives with direct development -or with a presumably similar specialized reproductive mode.…”