A light microscopic study of the saccule and lagena in certain catfishes

Abstract

The sacculi and lagenae from representatives of five species of catfishes were studied by light microscopy to provide an account of the anatomy of those structures and to determine whether phylogenetic changes can be detected in the inferior division of the membranous labyrinth among closely related ostariophysian fishes. The lagena showed little change among the forms used, while the saccule exhibited marked interspecies modifications. Anatomical variation was evident in the shape of the saccule, positioning of the interconnecting transverse canal, presence or absence of a release membrane, and, more notably, the position of the saccular macula and the shape and fluting pattern of the sagitta. Only minor variations were evident in the saccule and sagitta between the "primitive" conditions displayed in the siluroid form and those in the two bagroid representatives; in the latter forms, however, some positional modification of the posterior part of the macula from the "primitive" arrangement was present. In the bagroid representatives, the general morphology appeared to be stabilized early in the radiation, and individual changes suggest two lines of development within the group. The most significant modifications were evident in the loricaroid group where progression from the early representative to the more advanced form showed major changes in the inferior division of the labyrinth, including loss of the anterior part of the saccule and sagitta, modification of the remaining part of the sagitta, and repositioning of the saccular macula. The pattern changes in the saccule generally agreed with the phylogenetic sequence proposed by Chardon ('68) for catfishes.

Atlas of the developing inner ear in zebrafish

“…2C and 4D in Bang et al, 2001). Jenkins (1977) describes a longitudinal septum in the saccule of several catfish species. He suggests that once it has joined the saccule, the transverse canal continues rostrally along the dorsal aspect of the saccule and that the lumen of the canal remains partially separated from that of the saccule by this longitudinal septum.…”

“…The zebrafish ( Danio rerio , superorder Ostariophysi) has emerged as an important model organism for the study of vertebrate ear morphogenesis because development can be monitored and manipulated in vivo, the cristae and maculae are very similar to those of higher vertebrates, including humans, and mutagenesis screens have elicited a panel of genes involved in ear development (e.g., Jiang et al, 1996; Whitfield et al, 1996). There are several excellent descriptions of the adult ostariophysan ear (Retzius, 1881; Jenkins, 1977; Popper and Platt, 1983), including some specifically focused on the zebrafish (Platt, 1993; Bang et al, 2001). In addition, two key studies have provided elegant and detailed descriptions of early inner ear development in the zebrafish, up through 5 days postfertilization (Waterman and Bell, 1984; Haddon and Lewis, 1996).…”

Bony labyrinth morphology in early neopterygian fishes (Actinopterygii: Neopterygii)

“…In addition, these past investigations focussed almost exclusively on just two measurements: R, radius of curvature of the bony canal; and r, radius of curvature of the membranous canal; demonstrated to account for much of the variability observed in canal sensitivity (Jones and Spells, ). More recently, sporadic accounts of inner ear anatomy have targeted isolated taxa such as perch ( Perca : Ladich and Popper, ), arrowana ( Osteoglossum : Popper et al, ), and a number of catfishes (e.g., Ictalurus : Jenkins, ; Arius : Popper and Tavolga, ; Pterygoplichthys : Rogers, ).…”

Structure and Innervation of the Inner Ear Sensory Organs in an Otophysine Fish, the Upside–down Catfish (Synodontis nigriventrisDavid)

“…In the series Otophysi of the superorder Ostariophysi one finds a paired row of Weberian ossicles, which connect the swimbladder with the inner ear (Nelson 1984). The structure of the otophysine sensory organs has been described only in a few cases (Nakajima & Wang 1974;Jenkins 1977Jenkins , 1979Platt 1977;Popper & Tavolga 1981;Popper & Platt 1983). Quantitative studies of the innervation of the inner ear epithelia in fishes are limited to selected parts of the labyrinth or a single sensory organ (Wegner 1982;Saidel & Popper 1983a, b ;Corwin 1983Corwin , 1985Popper & Northcutt 1983;Jensen 1984;Popper & Hoxter 1984;Mathiesen 1985;Mathiesen & Popper 1987;Sento & Furukawa 1987;Sugihara & Furukawa 1989;Saidel et al 1990a, b ;Popper & Saidel 1990).…”