Comparative study of gill dimensions of three erythrinid species in relation to their respiratory function

Abstract

Gill dimensions were analysed in relation to body mass in three erythrinid fish, an air-breathing species, Hoplerythrinus unitaeniatus, and two ecologically distinct water-breathing species, Hoplias malabaricus and Hoplias lacerdae. Evidence was obtained of remarkable differences in patterns of increase in filament length, number of secondary lamellae, bilateral area of the secondary lamellae, total area of the secondary lamellae, and mass-specific area of the secondary lamellae among these three species. The analysis showed a large increase in respiratory surface area relative to body mass in H. malabaricus (b = 1.14) compared with Hoplias lacerdae (b = 0.81) and H. unitaeniatus (b = 0.66). This difference is mainly attributed to an increase surface area of individual secondary lamellae together with an increase in filament length and total number of secondary lamellae. The results indicate that the increased respiratory surface area of the H. malabaricus gill facilitates oxygen uptake in hypoxic environments as the fish grows and this suggests that gill dimensions may reflect ecological factors and not only respiratory requirements.

Response of mucous cells of the gills of traíra (Hoplias malabaricus) and jeju (Hoplerythrinus unitaeniatus) (Teleostei: Erythrinidae) to hypo- and hyper-osmotic ion stress

“…The structure and function of fish gills have been well described by several authors (Munshi, 1960;Hughes, 1966;Hughes & Munshi, 1979;Laurent, 1984;Roy & Munshi, 1986;Munshi & Singh, 1992;Fernandes et al 1994;Evans et al, 2005;Moraes et al, 2005;Banerjee, 2007;Fernandes et al 2007). The main cells that constitute the filament epithelium from the inner to the outer cell layer are non-differentiated, neuroepithelial, chloride, mucous and pavement cells.…”

Gill remodeling in fish – a new fashion or an ancient secret?

“…Similarly, hypoxia tolerance has been correlated with a large lamellar area in fishes (e.g. Fernandes et al, 1994;Chapman et al, 2000;Chapman and Hulen, 2001;Chapman et al, 2002). It is important to note that these relationships do not only show that fishes with high oxygen needs must have large lamellar surface areas.…”

A comparative analysis of putative oxygen-sensing cells in the fish gill

“…Although the traira is well adapted to life in shallow, stagnant, hypoxic lakes, the trairão inhabits well-aerated waters of central and southern Brazil (Rantin et al, 1993). Consequently, the traira has a higher hypoxia tolerance (Pc O 2=20·mmHg), higher Hb-O 2 affinity (P 50 =8.7·mmHg), larger respiratory surface area, lower metabolic rate and higher anaerobic capacity compared with the trairão (Pc O 2=35·mmHg) (Fernandes et al, 1994;Rantin et al, 1993;Perry et al, 2004). Filament and lamellar cell counts were different in the two Hoplias species, but the specific cell numbers did not produce the expected correlation to hypoxia tolerance (Fig.·3).…”