Mixophilus

These specimens were first collected in 1928 from a piece of land surrounded by water in the southern arm of the Cooum River at Chennai in India.

These centipedes were found coiled in loose soft mud where fishermen searched for polychaete worms of the genus Syllis.

[4][5] Later more specimens were collected from heaps of soil sticking out of the water closer to the Napier bridge.

Measurements of the pH level in the blood of Mixophilus specimens submerged in water reveal an increase in acidity, suggesting that these centipedes survive by relying on anaerobic metabolism, which increases carbonic and lactic acids in the blood, as well as cutaneous respiration.

These centipedes cannot survive indefinitely under water, however, and must clear the oxygen debt upon exposure to the air again.

[2] This centipede achieves this increase in oxygen uptake by pumping a larger volume of air into the tracheal system.

Allowed to recover after three days under water, for example, Mixophilus expands and contracts its main longitudinal tracheal trunks rhythmically at a rate reaching 22 to 25 pulsations per minute.

The spermataphores are oval like chicken eggs rather than laterally compressed like the spermatophores of a typical terrestrial centipede.

These spermataphores also lack the longitudinal cleft on one side from which the sperm emerge in the typical terrestrial centipede species.

This special adaptation for aquatic life allows females to pick up floating spermatophores from the water surface, where Mixophilus centipedes also feed.

The mandibles each feature a single lamella like a comb with very short slender teeth set closely in a row.

The basal element of each of the ultimate legs features numerous pores that open into a common pit near the sternite.