A new Reproduction mode for Frogs
of
the Genus Colostethus
Hugo Claessen
Photographs by the author
Introduction
Three members of the Belgian Herpetological Society, Jan Van der Meulen,
Ronny de Paepe and Hugo Claessen, made a trip during May and June 1999, to
different biotopes in French Guyana, to study reptiles and amphibians in the
wild. We normally select different places and whilst there, take
photographs of the fauna we see. It was on one of these trips that we took
photographs of Colostethus degranvillei in the neighbourhood of Cacao, a
village of monks, 80km from the capital Cayenne.
Colostethus degranvillei
This frog of the
family Dendrobatidae and the Colostethus genus, can be
found on the edges of small forest brooks or flowing creeks where its
habitat is the humid mossy stones in the river. At danger the frogs jump
into and hide under the water. The area where we found them was
very humid with temperatures around the 30°C being normal at this time
of the year, the end of the great rainy season.
It is known that Colostethus,
like other Dendrobatidae lay their eggs on the forest floor. The
male later takes the tadpoles onto his back and transports them to water
where they eat and grow till they metamorphose. The parents do not
generally care for their offspring. The only literature we could
find was a study about Colostethus degranvillei in Surinam (Hameleers
1982). C. degranvillei is a small brown frog with dark
spots that is difficult to differentiate from other species such as C.
beebee and C. brunneus.
On photographing the C. degranvillei we
saw what we assumed to be three small tadpoles on the back of the frog.
After the film was processed we saw that these were not in fact tadpoles but
small frogs. They were dark brown with small blue spots and two can be
seen on the photograph. If disturbed the small frogs remain on the back of
the parent. This means that the tadpoles were normally non-feeding larvae
that remain on the back of the male until they metamorphose, with no
free-swimming stage. Because this frog is not often maintained in
terraria, we know little about its reproduction and believed it to be like other
species of the genus.
This is a new reproduction mode that is not
described in any literature (Duellman W. & Trueb Linda, 1985). Duellmann
describes 33 different modes, but not this method.
Reproduction mode
As has already stated, this mode is not described and until there is a
professional publication we propose to name this method, modus 34.
According to BDG member Prof. Enrique La Marca (a
Venezuelan Colostethus specialist) of the University de Los Andes,
Venezuela, this is an unknown method, and our findings will be published in
Herpetological Review. (Claessen 1999)
Literature
Claessen H. 1999 A new reproduction modus
by Colostethus degranvillei. Herp. Review (3):
Duellman W. & Trueb Linda,
1985. Biology of Amphibians. Johns Hopkins University Press.
Hameleers 1982 Suggesties
voor de beschrijving van Colostethus degranvillei, S.O.L. Utrecht
