preservation. Areas of skin not covered by den- 

 ticles, around the gills for example, remained 

 darker; and edges of fins, where denticles are 

 sometimes either more numerous or are absent, be- 

 came a different shade of brown or black than the 

 rest of the body surfaces after preservation. The 

 material examined suggests that there is no diag- 

 nostic significance to brown or black color in mu- 

 seum specimens because color changes variously 

 after preservation. 



Excepting Apristurus, all Atlantic American 

 cat sharks now known are somewhat darker above 

 and lighter below, and furthermore, all have some 

 pattern of spots, blotches, or lines on the dorsal 

 surfaces, either lighter or darker than the back- 

 ground color. This does not pertain outside the 

 western Atlantic where the genus Galeus. for ex- 

 ample, is represented by some species without 

 markings, at least as adults, and other genera, 

 Parmatwrus for example, are represented by spe- 

 cies that are uniformly dark. 



The two species of western Atlantic Galeus have 

 color patterns that differ in intensity among the 

 three forms but show more resemblances to one 

 another than to color patterns in any other genus. 

 The patterns in Galeus are complex and difficult 

 to describe. Because pattern differences in this 

 genus are obscured by differences in intensity of 

 pattern, they are of low value in field identification 

 and other characters are not only more easily 

 described but also may be more reliable. 



Species of the three other genera as represented 

 in the western Atlantic, ScyliorMnus, Schroeder- 

 ichthys, and Halael/wrus, have essentially similar 

 basic color patterns but have diagnostically useful 

 modifications of the basic patterns. As indicated 

 by the few species of which juvenile examples are 

 available, and in its simplest and most persistent 

 form, the basic pattern consists of a series of seven 

 dorsal saddles or blotches. Depending upon 

 species, either more saddles may be present in in- 

 termediate positions or some of the main saddles 

 may be obscure. 



A parallel development of pattern in Scyli- 

 orhinus torrei Howell-Rivero and Si-hroederirh- 

 thys maculatus (one of the new species described 

 here) illustrates this. Both species have the seven 

 dorsal saddles appearing in some individuals but 

 generally more prominent in the young. In 

 adults of both species, however, the saddles may 



become quite indistinct with a partial substitution 

 of a pattern of small white spots on a tan back- 

 ground color. The tan color here is the color in 

 life and is not brought about by preservation. 

 The saddles seem to become more distinct with 

 preservation. In life or when freshly preserved 

 the two species are so similar in appearance of the 

 color and pattern that the rather great structural 

 differences may be overlooked easily. 



Variation in pattern within species in t he- 

 material at hand is moderate and reasonably well 

 defined. Figure 2A shows a rather extreme ex- 

 ample of the absence of full development of a retic- 

 ulate pattern characteristic of ScyliorMnus retifer 

 (Garman), whereas figure 2B shows a specimen 

 with the reticulate pattern fully, but not uni- 

 formly, developed. Although this pattern is 

 variable, it can be distinguished readily from pat- 

 terns made up of discrete black spots or white 

 spots. 



Reproduction 



Most cat sharks lay eggs in cases which, when 

 first laid, are impervious and sealed against the 

 entry of seawater. During development of the 

 embryo, slits appear in corners of the egg cases to 

 permit a flow of sea water through the egg case. 

 Tendrils, one from each of the four corners of the 

 egg case, attach it to objects on the bottom when 

 the eggs are laid. 



In addition to information on the egg laying 

 habits of Apristurus riveri, available records and 

 material show that ScyliorMnus retifer and 

 Schroederichthys maculatus lay eggs. No positive 

 information is at hand for other western Atlantic 

 species, but an egg case with developing embryo 

 (fig. 3) may be presumed to be either Scylior- 

 Mnus meadi or S. torrei on indirect evidence of 

 locality. 



The genus Galeus is represented in the eastern 

 Atlantic, including Icelandic waters, by four 

 species among which are two little-known forms 

 without markings or color patterns; these were 

 described from specimens from the Hebrides and 

 from Iceland. The remaining eastern Atlantic 

 forms include Galeus melastom/us Rafinesque, an 

 egg layer, and Galeus poll! Cadenat, an ovovivip- 

 arous species that retains vgg* in the oviduct until 

 after the egg shell has been absorbed and after the 

 embryo has completed absorption of the yolk 

 saC. No positive evidence has been found to 



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U.S. FISH AND WILDLIFE SERVICE 



