110 



Abstract.— Three new species of hag- 

 fish (Myxinidae, Eptatretus) are de- 

 scribed from the Galapagos Islands. 

 Ecuador. These are the first myxinids 

 known from this region and the first 

 species of Eptatretus with five, six. and 

 eight gill pouches reported from the 

 eastern Pacific. A key to their identifi- 

 cation is presented. 



Three new species of hagfish 

 (Myxinidae, Eptatretus) from the 

 Galapagos Islands 



Charmion B. McMillan 



Marine Biology Research Division, 0202 

 Scripps Institution ol Oceanography 

 La Jolla, California 92093 



E-mail address charmcmig)|uno com 



Manuscript accepted 7 April 1998. 

 Fish. Bull. 97:110-117 (1999). 



The Galapagos Islands consist of 

 about ten principal islands and over 

 100 smaller ones on the equator 

 about 500 miles off the coast of Ec- 

 uador. The biodiversity found in 

 these islands by Darwin (1896) is 

 also expressed in the marine fauna 

 (McCosker, 1997); three new species 

 of hagfish were found in only eight 

 specimens from four trap sets (Fig. 

 1 ). An exploration off South America 

 and the Galapagos Islands in 1891 

 by the U.S. Fish Commission 

 Steamer Albatross reported only 

 one species of hagfish, Myxine 

 circifrons Garman ( 1899), taken off 

 the Gulf of Panama. Several species 

 of Eptatretus with from nine to four- 

 teen gill pouches have since been 

 reported from the eastern Pacific 

 coast (Wisner and McMillan, 1990), 

 and one species with seven gills, E. 

 laurahubbsae McMillan and Wisner 

 (1984), from the Juan Fernandez 

 Islands, Chile. The new species de- 

 scribed below are the first hagfish 

 reported from the Galapagos Is- 

 lands, and the first Eptatretus with 

 five, six, and eight gill pouches 

 known from the eastern Pacific. 

 Until the formation of the Panama- 

 nian land bridge there was a long- 

 standing connection between the 

 Caribbean and eastern Pacific, 

 which provided a passage for hag- 

 fish to move into the eastern Pacific 

 from the Caribbean. These new spe- 

 cies may be more closely related to 

 the Eptatretus with five to eight 

 gills found in the Caribbean and 

 western Atlantic than to any cur- 



rently known from the eastern Pa- 

 cific. Future collecting efforts along 

 the coast of Ecuador may reveal 

 Eptatretus similar to those found off 

 the Galapagos Islands; however, 

 until further material is available 

 and genetic studies are made for 

 comparison, we can only speculate 

 on possible origins of these Gala- 

 pagos hagfishes. 



Although the body color of most 

 species of Eptatretus is brown to 

 black, Fernholm ( 1991 ) described a 

 species of Eptatretus on the basis of 

 one specimen with a highly unusual 

 pink body, stating that its color was 

 probably caused by diet. Of the 

 eight specimens reported here, the 

 seven larger ones are dark purplish- 

 brown to black or dark gray where 

 the slime has not been removed. 

 The smallest specimen (about 142 

 mm), possibly an albino, is ivory to 

 light tan. Not enough is known 

 about the early development of hag- 

 fish to determine if this tiny speci- 

 men would have become darker 

 with age. Albinism has been re- 

 ported by Dean ( 1903) and Jensen 

 ( 1959), and I have collected one, an 

 adult E. deani (Evermann and 

 Goldsborough, 1907), which was 

 pinkish-white when alive and light 

 tan color in formalin. 



Head grooves are present near 

 the eyespots of the seven large 

 specimens, but not on the smallest 

 hagfish. These grooves, found in 

 many other species of Eptatretus 

 (McMillan and Wisner, 1984) and 

 once thought similar to lateral lines, 



