Development of the supraorbital and mandibular lateral line canals in the cichlid, archocentrus nigrofasciatus

Abstract

The development of two of the cranial lateral line canals is described in the cichlid, Archocentrus nigrofasciatus. Four stages of canal morphogenesis are defined based on histological analysis of the supraorbital and mandibular canals. "Canal enclosure" and "canal ossification" are defined as two discrete stages in lateral line canal development, which differ in duration, an observation that has interesting implications for the ontogeny of lateral line function. Canal diameter in the vicinity of individual neuromasts begins to increase before ossification of the canal roof in each canal segment; this increase in canal diameter is accompanied by an increase in canal neuromast size. The mandibular canal generally develops later than the supraorbital canal in this species, but in both of these canals development of the different canal segments contained within a single dermal bone is asynchronous. These observations suggest that a dynamic process requiring integration and interaction among different tissues, in both space and time, underlies the development of the cranial lateral line canal system. The supraorbital and mandibular canals appear to demonstrate a "one-component" pattern of development in Archocentrus nigrofasciatus, where the walls of each canal segment grow up from the underlying dermal bone and then fuse to form the bony canal roof. This is contrary to numerous published reports that describe a "two-component" pattern of development in teleosts where the bony canal ossifies separately and then fuses with an underlying dermal bone. A survey of the literature in which lateral line canal development is described using histological analysis suggests that the occurrence of two different patterns of canal morphogenesis ("one-component" and "two-component") may be due to phylogenetic variation in the pattern of the development of the lateral line canals.

Diversity of Lips and Associated Structures in Fishes by SEM

“…Neuromasts can be found on the entire body surface including the tail with the cupulae extending into the water (Schellart & Wubbels, 1998;Eastman & Lannoo, 2003;Tarby and Webb, 2003;Sane et. al., 2009).…”

The lateral line microcosmos

“…Alternatively, the association may be essential, if the formation of dermal bones and of canals both depend on a single initiation event ("onecomponent" view). Dermal bones and canal walls were shown to derive from a single ossification center in a species with many derived characters, leading to the hypotheses that the "one-component" development is a derived feature (Tarby and Webb 2003).…”

Quantitative Aspects of the Spatial Distribution and Morphological Characteristics of the Sea Bass (<i>Dicentrarchus labrax </i>L.; Teleostei, Serranidae) Trunk Lateral Line Neuromasts

“…This observation constitutes a preliminary finding that requires further substantiation. Previous reports [Coombs et al, 1989;Tarby and Webb, 2003] suggested that the development of canal neuromasts is subordinate to the mechanical limits set by the growth of the dermal bone. Accordingly, it was not surprising to notice that, as observed in Cottidae [Janssen et al, 1987] and Cichlidae [Münz, 1989;Tarby and Webb, 2003], the size of canal neuromasts was positively correlated with fish size.…”

“…Previous reports [Coombs et al, 1989;Tarby and Webb, 2003] suggested that the development of canal neuromasts is subordinate to the mechanical limits set by the growth of the dermal bone. Accordingly, it was not surprising to notice that, as observed in Cottidae [Janssen et al, 1987] and Cichlidae [Münz, 1989;Tarby and Webb, 2003], the size of canal neuromasts was positively correlated with fish size. Consequently, and in agreement with Coombs et al [1989] and Webb [1989b], the size of superficial neuromasts, which are free from morphological constraints, presents a wide range of values and, at the same time, their number increases with fish size [Blaxter et al, 1983;Blaxter, 1987;Prié-Granié;Harvey et al, 1992;Higgs and Fuiman, 1996;Appelbaum and Riehl, 1997;Poling and Fuiman, 1997;Webb and Shirey, 2003].…”