Oxygen uptake through water during early life of Anabas testudineus (Bloch)

Abstract

The 02 consumption (mg/hr) through water in case of Anabas testudineus during development and growth has been measured and its relationship to body weight or length studied .The logarithmic plot of 0 2 uptake through water either against body weight or length suggested a statistically significant (P > 3 .53) two-component curve, the point of intersection being at 1 I mg body weight and 1 .78 cm body length . These are the theoretical values of weight or length at which the responsibility of supplementing nearly 40% of the total 0 2 demand through the newly developed air breathing organ falls in the early life of the fish. One of the impelling causes forcing developing fry of Anabas to adopt a bimodal gas exchange machinery seems to be 4 fold increase in the diffusion distance at the gills .

Oxygen uptake through water during early life in Channa punctatus (Bloch) (Pisces; Ophicephaliformes)

“…A similar finding was made for Anabas testudineus (Mishra & Singh 1979b) and Heteropneustes fossilis . A possible explanation for this seems to be a comparatively faster growth of the gill surface area and almost no change in the diffusion distance at the gills once the air breathing organs are established.…”

“…The relationship existing between 02 uptake and body size (weight) in Channa punctatus is similar (Table 2) to that of Anabas testudineus (Mishra & Singh 1979b). In the case of body length, the relationship changes considerably.…”

“…The larvae of Anabas testudineus (Mishra & Singh 1979b) and Heteropneustes fossilis ) depend on aquatic respiration alone in the beginning but as soon as they are capable of gulping air, oxygen uptake through water declines. The present study aims at measuring 02 uptake in the larval life of the air breathing fish, Channa punctatus.…”

O2 uptake through water during early life of Heteropneustes fossilis (Bloch)

“…When the fry adopt to bimodal breathing habit, the 02 uptake through water declines, and so does the slope value (0.71). Almost a similar trend in deflection of the slope for 02 uptake has been reported by Mishra & Singh (1979) in the case of Anabas testudineus. For example, a slope of 0.95 at the time of totally relying on aquatic respiration and meeting the entire 02 demand of the body, is changed to 0.587 while practising bimodal gas exchange.…”

“…These are: Heteropneustesfossilis , Clarias batrachus (Munshi et al, 1976), Anabas testudineus (Munshi & Dube, 1973) and Amphipnous cuchia (Patra et al, 1978, Singh & Thakur, 1979. However, these studies are limited to the measurement of 02 uptake on adult specimens of air breathing fishes and the only account available so far for the early stages of development is that of Mishra & Singh (1979) on Anabas testudineus. The purpose of this study has been to measure 02 uptake rate through water in the larvae of Heteropneustes fossilis which rely wholly on aquatic respiration in the beginning but later acquire the habit of gulping atmospheric air in addition to gas ex-change carried out at the gills in water.…”