1969/12/05 by Harley W. Reno · 1 citation
Environmental Science · Agricultural and Biological Sciences · #Physiological and biochemical adaptations #Cephalopods and Marine Biology #Fish biology, ecology, and behavior
paper · doi:10.2307/1441800
On the basis of lateral-line canal and brain patterns, eye sizes and positions, barbel lengths, and quantitative and qualitative measurements of neuromasts (canal and skin) and taste buds, it was possible to correlate the known ecologies of some Hybopsis with specialized structures. Histological examination of the lateral-line canals of Hybopsis revealed the epithelial lining to be stratified squamous instead of simple cuboidal and pseudostratified columnar as has been reported elsewhere. The canal epithelium in all Hybopsis except H. gracilis has few if any goblet cells; consequently, in lieu of mucus, the canals are filled with water in which diatoms and protozoa may live. En face sections of canal neuromasts showed neuromasts to be segmentally connected via of mesenchyme. These cords are described and discussed in relation to the ectodermal origin of the neuromasts. The superficial neuromasts of H. crameri are unique among teleosts, for each neuromast possesses several (2-9) extracellular, protozoan-like structures. These structures were examined and compared with similar structures reported in neuromasts of some anurans and urodeles. In Hybopsis it was concluded that neuromasts do not evoke bone, but rather are passively enclosed by bone. H. harperi appears more closely related to members of the Hybopsis species group than to members of the Erimystax group, and H. labrosa is more closely related to the Erimystax species group than to the Hybopsis group. Morphologically, it seems doubtful that the barbelled minnows included in the genus Hybopsis are closely related phylogenetically. However, because knowledge of the phylogenetic relationships of most North American cyprinids is poor, it is difficult to evaluate the exact positions of many of the distinct subgenera now placed in Hybopsis.