Surface ultrastructure of the gill filaments and the secondary lamellae of the catfish,Rita rita, and the carp, Cirrhinus mrigala

Abstract

Surface ultrastructures of gill filaments and secondary lamellae of Rita rita and Cirrhinus mrigala, inhabiting different ecological habitat, were investigated to unravel adaptive modifications. R. rita is a sluggish, bottom dwelling carnivorous catfish, which inhabits regions of river with accumulations of dirty water. It retains its viability for long time if taken out of water. C. mrigala is an active bottom dwelling Indian major carp, which lives in relatively clean water and dies shortly after taken out of water. In R. rita, gill septa between gill filaments are reduced. Microridges on epithelial cells covering gill filaments are often continuous and arranged concentrically. Secondary lamellae are extensive. The epithelium appears corrugated, show irregular elevations and shallow depressions, and microridges on epithelial cells appear fragmented. In C. mrigala, in contrast, the gill septa are extensive. Microridges on epithelial cells covering gill filaments are fragmented. Secondary lamellae are less extensive. The epithelium appears smooth and microridges on epithelial cells are relatively inconspicuous. These differences have been considered adaptive modification in relation to habit and ecological niches inhabited by two fish species. Presence of mucous goblet cells on gill filaments is discussed in relation to their functions including precipitation of the sediments and preventing clogging of gill filaments. Infrequent mucous goblet cells in the epithelium of secondary lamellae in two fish species are considered an adaptation, minimizing thickness of the epithelium to reduce barrier between blood and water for favoring gasses exchange with increased efficiency.

Gill Morphology in Two Bottom Feeder Mediterranean Sea Fishes: Grey Gurnard Fish (Eutrigla gurnardus, Linnaeus, 1758) and Striped Red Mullet Fish (Mullus barbatus surmuletus, Linnaeus, 1758) by Scanning Electron Microscopy

“…There are great variations in the number of gill arches between the different fish species; in the present study there are three pairs of gills in the striped red mullet, as noted in the puffer fisch (Abumandour & Gewaily), however, the four pairs of gills is the common number in most teleost fishes as in the present investigation in the grey gurnard (Hughes & Grimstone, 1965;Hughes & Morgan;Hossler et al, 1985;Eiras-Stofella et al, 2001;Eiras-Stofella & Fank-de-Carvalho, 2002;Zayed & Mohamed;Cinar et al, 2009;Díaz et al, 2009;Kumari et al, 2009;Kumari et al, 2012;Alsafy;Elsheikh). However, there are five pairs of gills, but the fifth pair is ill developed and devoid from any gill filaments as noted in catfish (Zayed & Mohamed;Kumari et al, 2005;Elsheikh), in contrast, in Senegal sole (Arellano et al, 2004) reported that the fifth pair is well-developed and contains gill filaments.…”

“…Moreover, in freshwater fish Prochilodus scrofa Steindachner and in seawater Eugerres brasilianus, the gill filaments are shorter on both extremities of gill arch and in the strong curvature angle region (Eiras-Stofella & Charvet-Almeida, 1998, 2000, however, Kumari et al, (2012) in catfish and Carp reported that, the length of the gill filaments is shorter on one side than on the other corresponding side of the gill arch.…”

Morphological Studies on the Gills of Puffer Fish (Lagocephalus sceleratus, Gmelin, 1789)

“…There are great variations in the number of gills between the different fish species; in the present study there are three pairs of gills, however, four pairs of gills is the common number in most teleost fishes (Hughes & Grimstone, 1965;Hughes & Morgan;Hossler et al, 1985;Eiras-Stofella et al, 2001;Eiras-Stofella & Fank-deCarvalho, 2002;Zayed & Mohamed;Cinar et al, 2009;Díaz et al, 2009;Kumari et al, 2009Kumari et al, , 2012Alsafy;Elsheikh). However, there are five pairs of gills but the fifth pair is ill developed and devoid from any gill filaments as noted in catfish (Zayed & Mohamed;Kumari et al, 2005;Elsheikh), in contrast, in Senegal sole (Arellano et al, 2004) reported that the fifth pair is well-developed and contain gill filaments.…”

“…Moreover, in freshwater fish Prochilodus scrofa Steindachner and in seawater Eugerres brasilianus, the gill filaments are shorter on both extremities of gill arch and in the strong curvature angle region (Eiras-Stofella & Charvet-Almeida, 1998, 2000, however (Kumari et al, 2012) in catfish and Carp reported that, in gill arch the length of gill filaments is shorter on one side than the other.…”

Gills of the medaka (Oryzias latipes): A scanning electron microscopy study

“…Mucus is trapped and held within the microridges. The mucus layer on the gill surface may (1) reduce the abrasive action of suspended particles in water during ventilation (Kumari, Mittal, & Mittal, ; Moron & Fernandes, ), (2) be involved in osmoregulatory processes through the trapping of ions from freshwater (Monteiro, Oliveira, Fontainhas‐Fernandes, & Sousa, ), and/or (3) be implicated in the immune/barrier system. Several defense factors have been identified in mucus (immunoglobulins, lectin, lysozyme, and complement, etc.)…”