Reproductive Behavior of the Mottled Sculpin, Cottus bairdi Girard

Copeia ◽  
1963 ◽  
Vol 1963 (2) ◽  
pp. 317 ◽  
Author(s):  
Thomas Savage
Author(s):  
W.R. Jones ◽  
S. Coombs ◽  
J. Janssen

The lateral line system of the mottled sculpin, like that of most bony fish, has both canal (CNM) and superficial (SNM) sensory end organs, neuromasts, which are distributed on the head and trunk in discrete, readily identifiable groupings (Fig. 1). CNM and SNM differ grossly in location and in overall size and shape. The former are located in subdermal canals and are larger and asymmetric in shape, The latter are located directly on the surface of the skin and are much smaller and more symmetrical It has been suggested that the two may differ at a more fundamental level in such functionally related parameters as extent of myelination of innervating fibers and the absence of efferent innervation in SNM. The present study addresses the validity of these last two features as distinguishing criteria by examining the structure of those SNM populations indicated in Fig. 1 at both the light and electron microscopic levels.All of the populations of SNM examined conform in general to previously published descriptions, consisting of a neuroepithelium composed of sensory hair cells, support cells and mantle cells, Several significant differences from these accounts have, however, emerged. Firstly, the structural composition of the innervating fibers is heterogeneous with respect to the extent of myelination. All SNM groups, with the possible exception of the TRrs and CFLs, possess both myelinated and unmyelinated fibers within the neuroepithelium proper (Fig. 2), just as do CNM. The extent of myelina- tion is quite variable, with some fibers sheath terminating just before crossing the neuroepithelial basal lamina, some just after and a few retaining their myelination all the way to the base of the hair cells in the upper third of the neuroepithelium. Secondly, all SNMs possess fibers that may, on the basis of ultrastructural criteria, be identified as efferent. Such fibers contained numerous cytoplasmic vesicles, both clear and with dense cores. In regions where such fibers closely apposed hair cells, subsynaptic cisternae were observed in the hair cell (Fig. 3).


1980 ◽  
Vol 66 (5) ◽  
pp. 828 ◽  
Author(s):  
George A. Conder ◽  
Reed Y. Oberndorfer ◽  
Richard A. Heckmann

Copeia ◽  
1986 ◽  
Vol 1986 (1) ◽  
pp. 91 ◽  
Author(s):  
Denise Hoekstra ◽  
John Janssen

1989 ◽  
Vol 67 (11) ◽  
pp. 2711-2720 ◽  
Author(s):  
Alex E. Peden ◽  
Grant W. Hughes ◽  
W. E. Roberts

Previously known within Canada from the Flathead River, nominal Cottus confusus also occur in the Kettle, Columbia, and Slocan rivers of British Columbia. The latter populations are similar to those from Washington, and possess a post-maxillary pore, lower numbers of pectoral rays, prickles behind the pectoral fin, and a smooth head. They are sympatric with nominal Cottus bairdi, with some individuals morphologically intermediate between the two species. Flathead River samples of nominal C. confusus differ from Columbia River populations in absence of the pore and prickles, higher fin ray counts, and larger head papillae. Specimens of nominal C. bairdi previously reported from the St. Mary River (Saskatchewan and Nelson drainages) and Milk River (Missouri River drainage) of Alberta are similar to Flathead River C. confusus, with others intermediate between Flathead River C. confusus and Columbia River populations of C. bairdi and C. confusus. Differences between Flathead River and Columbia River samples suggest that these populations require separate status in Canada. Similkameen River samples of C. bairdi are morphologically variable, individuals from upstream populations having some characters similar to those of C. confusus. A thorough study of C. bairdi and C. confusus in the United States is needed to redefine species limits.


1990 ◽  
Vol 29 (1) ◽  
pp. 43-50 ◽  
Author(s):  
John Janssen ◽  
Sheryl Coombs ◽  
Shirley Pride

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