SOUTHERN DISTRIBUTION OF 



THE ATLANTIC WHITESIDED DOLPHIN, 



LAGENORHYSCHUS ACUTUS, IN 



THE WESTERN NORTH ATLANTIC 



Two mass strandings of the Atlantic whitesided 

 dolphin, Lagenorhynchus acutus, in New 

 England— Wellfleet, Mass., 11 May 1973 and Ed- 

 munds, Maine, 6 September 1974 — initiated in- 

 vestigation at the New England Aquarium, Bos- 

 ton, into this species' life history and pathobiology. 

 Previous distribution records for this species in 

 the United States were reported by Cope (1876), 

 True ( 1885, 1889), and Schevill ( 1956). Most refer- 

 ences define this dolphin's southern distribution 

 as Cape Cod, Mass. We believe this is based on a 

 206 cm female reported to have been collected near 

 Portland, Maine, and described by Cope ( 1876) as 

 L. perspicillatus (= L. acutus). Norton (1930) re- 

 described the correct collecting site as Cape Cod. 



The first confirmed Cape Cod report, although 

 not a stranding, was on 14 September 1954 when a 

 school sighting and harpooned specimen were re- 

 ported by Schevill (1956). This school, about 12 

 animals, was located 93 km east of Cape Cod in 

 water 145 m deep (Figure 1, number 3). 



The following accounts, arranged in chronologi- 

 cal order, update our present knowledge of this 

 species' southernmost known occurrence in the 

 western North Atlantic. Information is based 

 upon stranding records of the Smithsonian In- 

 stitution and the New England Aquarium, along 

 with an examination of the collections of the 

 American Museum of Natural History, New York, 

 N.Y.; Academy of Natural Sciences, Philadelphia, 

 Pa.; U.S. National Museum, Washington, D.C.; 

 and the Museum of Comparative Zoology, Har- 

 vard University, Cambridge, Mass. Paragraph 

 numbers below correspond to locality numbers in 

 Figure 1 and to reported body measurements 

 given in Table 1. Abbreviations for collection 

 numbers are as follows: MCZ = Museum of Com- 

 parative Zoology, Harvard University, NEA = 

 New England Aquarium, USNM = U.S. National 

 Museum. 



1. One male (USNM 22934) captured by the 

 U.S. Fisheries schooner Grampus 20 mi (37 km) 

 south of Montauk, Long Island, N.Y. (lat. 40°38' 

 N, long. 71°49' W), 19 May 1888. This specimen 

 was reported to have been captured from a school 

 of about 100 animals. 



FISHERY BULLETIN; VOL. 78, NO. 1. 1980. 



O Sighting 



• Single st randing 



A Sighting plus 



captured specimens 



Figure l. — Southernmost east coast locations of known Atlan- 

 tic whitesided dolphin sightings. Nximbers refer to specimens 

 described in Table 1 and in text. 



2. One female (USNM 22942), also captured 

 by the Grampus, taken south of Cape Cod Islands 

 (lat. 40°43' N, long. 70°32' W). No date recorded 

 but because of its proximity to the prior animal's 

 catalog number, we believe this animal was taken 

 on the same cruise. 



3. One female (MCZ 48548) harpooned from a 

 small school off Cape Cod (lat. 41=35' N, long. 

 68=55' W), 14 September 1954 (Schevill 1956). 



4. One skull (MCZ 48549) collected during the 

 winter 1954-55 at South Beach, Martha's Vine- 

 yard, Mass. 



5. One specimen washed ashore live at Ocean 

 Beach, Fire Island, Long Island (lat. 40=39' N, 

 long. 73°09' W), April 1971. Length estimated at 

 about 7.5 ft (229 cm), sex undetermined. Skull 

 measurements: condylobasal length, 391 mm; ros- 

 trum length, 196 mm; tooth width, up to 4 mm; 



33- 



dental formula 



34-34 



167 



