A Case of Abnormality in the Testes of Mastacembelus armatus (LACEP)

Abstract

During investigations on the morphology of Mastacembelus armatus an anomaly was observed in the male gonads of a fish, which was caught from Kalinadi in the vicinity of Meerut. Usually the testes are elongated, cylindrical and unequal in length, the right being smaller than the left. They are attached to each other and to the alimentary canal by mesentery and to the air bladder by mesorchia, which extends in front in the form of two fine threads. In the specimen under report (Fig. 1), the anterior parts of the testes were found intimately fused although the two mesorchia were distinct. A section of this region (Fig. 2) shows that the fused parts of the testes are enveloped in a common sheath of peritoneum, there being no demarcation between their tissues.
The length of these testes, when compared with the normal testes of another specimen of the same size, was found to be nearly equal. The length of the right and left testes in a normal specimen of 48.5 cm. was 9.3 and 9.5 cm. respectively, while the length of the two testes in this specimen (Fig. 1) of 49.7 cm. was 9.7 cm.
This abnormality in the fish is rare and has not so far been reported. It appears that the two testes got fused through their peritoneal covering during development.
I wish to express my gratitude to Dr. B. M. SINHA for the help in preparing the note.