Eleutherodactylus jasperi (Fig. 1) is an ovoviviparous
frog that gives birth to 3-5 metamorphosed
froglets following brooding by the female in a chamber
formed of the fused posterior parts of the oviducts
(Drewry and Jones, ’76; Wake, ’78a). It is a
member of the highly speciose genus Eleuthero-Fig. 1. Female Eleutherodactylus jasperi (20.5 mm snoutvent
length [SVL]) with its clutch of three near-birth froglets
(arrows; 6.2-7.0 mm SVL) in the oviducts.
dactylus, all of whose approximately 300 members
are direct developers, except E. jasperi, the ovoviviparous
taxon. The species may well be extinct,
for it has not been collected in its restricted habitat
on Puerto Rico for several years (D. S. Townsend,
personal communication).
The gestation period is approximately 33 days,
for frogs gave birth 33 days after they were found
in amplexus (Drewry and Jones, ’76). Internal fertilization
is inferred, but has not been observed.
(Other Eleutherodactylus are demonstrated to have
internal fertilization, though they are direct developers
[Townsend et al., ’811). Wake (’78a) described
the morphology of the reproductive organs and the
intra-oviductal development of the tadpoles of E.
jusperi. Corpora lutea were not observed in the ovaries
of pregnant females. The oviducts of the females
are modified for retention of the developing embryos
by having the posterior 5 mm of the 12 mm oviducts
fused as a “uterus.” When the female is pregnant,
this part of the oviducts is highly distended,
and the epithelial lining is lower in height than
that of the anterior oviduct (Fig. 2). The “uterine”
epithelial cells also lack cilia and microvilli present
on more anterior cells. The cells of the anterior
duct are secretory; there is an abrupt transition
to nonsecretory columnar epithelium low in the