Hymenochirus, Cecere (1998)

This is my illustration from a living specimen of Hymenochirus at about 25 days of age.  Its overall length is just over 1 cm.  A limb bud can be seen below the tail fin.  This is a well-fed tadpole as indicated by the rounded abdomen.  The eyes protrude from the skull and are angled slightly downward. The mouth is superior and rests between the eye protrusions.  Based on the description in RABB (1963) this is a specimen of H. boettgeri.  The iridocytes on this specimen at 25 days were silver but many members of this batch had golden iridocytes at earlier stages.  The longitudinal markings on the tail are not obvious until week 3.
Rabb and Sokol disagree on many aspects of Hymenochirus egg charactaristics, egg development, and tadpole development. I have written an article that addresses the discrepancies in two of their research papers: Rabb, 1963 and Sokol, 1962.

Sokol (1962) Copeia 2:274

"Fig. 1. Young larvae of Hymenochirus.  A.  H. boettgeri at hatching.  Note ventrally produced cement gland.  Actual size 2.5 mm.  B.  H. curtipes 24 hours after hatching.  Vertical groove is olfactory pit; horizontal groove marks dorsal rim of developing oral tube (arrow).  Actual size 3.5 mm."

Hymenochirus curtipes, Sokol (1959) Zoologisher Anzeiger 162:156

This illustration is from a paper written in German. I include it here because it is repeatedly referred to in Sokol's1962 paper.

Sokol (1962) H. boettgeri

Hymenochirus boettgeri, Sokol (1962) Copeia 2:275

"Fig. 2.  Fully grown tadpoles of Hymenochirus boettgeri (21mm). A. Dorsolateral view.  B. Ventrolateral view.  C. Head of tadpole (18 mm) preserved with mouth open."

Sokol (1962) H.boettgeri

Hymenochirus boettgeri, Sokol (1962) Copeia 2:276
"Fig. 3.  Metamorphosing Hymenochirus boettgeri tadpole(22 mm, 9mm snout-vent). Note the reduction of the supralabial pad and the beginning retreat of the articulation of the lower jaw." "Fig.4.  Metamorphosing tadpole of Hymenochirus boettgeri (19.5 mm; snout-vent 10 mm).  The oral tube has just split.  The two anterior tabs on the remaining labial folds mark the posterior corner of the larval mouth."

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