THE VERTEBRATES OF SCOPE 

 NOVEMBER 7 - DECEMBER l6, 1956 

 By 

 Robert Cushman Murphy 1/ 

 American Museum of Natural History 



My journal included observations on all 

 vertebrates except the small and larval 

 fishes taken in net hauls. Collecting of 

 sea birds from a skiff was undertaken at 

 oceanographic stations whenever weather 

 permitted, resulting in the acquisition of 50 

 specimens. The birds, collected primarily for 

 identification, have not yet all been studied 

 for subspecific determination. For the 

 purpose of this report specific status is in 

 most cases adequate. A later publication will 

 include data on taxonomy, habits, and stomach 

 contents. 



FISHES 



The bulk of the fishes captured, and now at the 

 Scripps Institution, are outside my province. 

 The following notes are restricted to larger 

 or otherwise readily observable species. 



Ginglymostoma cirratum. Nurse shark. An 

 example about 1.5 m. in length swam under and 

 around the skiff shortly after daybreak of 

 Nov. Ik, k^> miles SW of Acapulco (surface water 

 29.6°C). 



Prionace glauca. Blue shark. Observed several 

 times in the "Dome" area, S of latitude 10°N 

 and 200 or more sea miles W of Costa Rica. On 

 Nov. 22, at 09°05'N, 89 <> 3C W, a young example 

 only 65 cm. in length rubbed persistently 

 against the flanks and bottom of the skiff 

 until it was hauled aboard by the tail 

 (surface water 25.7°C). 



Carcharias . Sharks of this genus or type 

 were observed almost daily in tropical waters. 

 They frequently assembled around the Stranger 

 when she was on station. In common with 

 certain other oceanic fishes, they were 

 strongly drawn toward any flotsam large enough 

 to cast a shadow. Bamboo poles and glass net- 

 floats proved sufficient to serve as an 

 attraction. 



On Nov. 22, in the position noted under the 

 foregoing species, a Carcharias 2 m. in length 

 rubbed and banged the skiff for ten minutes, 

 sweeping its tail along the gunwale and 

 splashing showers of water all over the craft. 

 Such behavior is sometimes interpreted as an 

 effort to remove ectoparasites but it may 

 represent merely a thigmotactic drive. 



Galeocerdo tigrinum . Tiger shark. On Nov. 16, 

 at 12" V7 1 N, 94°15' W, about 215 miles Off the 

 head of the Gulf of Tehuantepec, a young and 

 spotted example, less than 2 m. in length, 

 clung for some time to the vicinity of the 

 skiff (surface water 28°C). 



Mobula 

 7* 



Jumping ray. On Nov. ik, at l6°l6' N, 

 100°27' W. roughly k5 miles SW of Acapulco, a 

 ray about 60 cm. in lateral extent jumped and 

 somersaulted six times just ahead of the skiff 

 (surface water 29.6°C). 



Other rays, not identified, were frequently 

 seen during the cruise. 



1/ Dr. Murphy's participation in the cruise 

 was made possible through a gift to the American 

 Museum of Natural History from Mr. Edgar J. Marston 

 of La Jolla, together with a grant from the Council 

 of the Scientific Staff of the Museum. 



Manta birostris . Giant ray; manta. The 

 specific name may possibly be open to question, 

 but the ray was indistinguishable in the field 

 from the Atlantic form. 



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