Morphometries of the respiratory organs of the Indian green snake‐headed fish, Channa punctata

Abstract

Measurements of the dimensions of the different gills and the suprabranchial chambers have been made and the data analysed with respect to body weight using logarithmic transformations (Y = aW b ). The slope (b) for area of the total gill surface is 0–592 and for the supra‐branchial chamber 0–696, and their combined respiratory surface: 0–623. The slope values for the surface areas of the 1st, 2nd, 3rd and the 4th gill arches were 0–595,0–578,0–614 and 0–572 respectively. The slope for secondary lamellae/mm is –0138 and that for the bilateral surface area of an average‐sized lamella 0–304. These results indicate differences in growth patterns for the dimensions of the different gills. The growth‐related decrease in the number of secondary lamellae/mm and size of an average secondary lamella together with evidence from “drowning” experiments and diffusing capacity calculation, suggest that this fish is better adapted for aquatic respiration than Anabas or Saccobranchus. The slopes for the total respiratory surface area and gill area seem to be comparatively low in this species.