80 U.S. NATIONAL MUSEUM BULLETIN 2 02 Vol.3 



Caudal fin moderately forked in smaller specimens, less so in larger 

 ones. 



Color in alcohol. -~Hea,d and body dark brown; pectoral fm dark 

 brown, lighter near tips; pelvic fin blackish, margin of first ray light 

 near tip; dorsal, anal, and caudal fin nearly uniform dark brown. 



Ecology. — Mainly an offshore form, at or near surface over deep 

 water or attached to other fishes in these waters. 



Hosts. — -The above three specimens were taken from a shark, offshore, 

 over deep water. The literature and unpublished host data in various 

 museum collections indicate that sharks of several species are the 

 most common hosts of R. remora. Some of these shark hosts are the 

 tiger shark Galeocerdo cuvieri; hammerhead shark Sphyrna zygaena; 

 Thalassorhinus sp.; Carcharhinus sp.; great blue shark Prionace 

 glauca; and the sharpnose shark Scoliodon. Other hosts are the devil 

 ray Manta; sharp tail ocean sunfish Masturiis lanceolatus; marlin 

 Makaira sp.; sailfish Istiophorus; and sea turtles. 



Remarks. — This species is widely distributed in all warm oceans 

 and known from a number of areas in Oceania, the Phoenix, Fanning 

 and Hawaiian islands, Easter Island, Tahiti, and the Low Archipelago. 

 Two species commonly confused with R. remora, particularly the 

 smaller specimens, are R. hrachyvtera and R. osteochir. A single 

 character, the total number of gill rakers, will separate R. remora 

 from these species; R. remora has 28 or more rakers as opposed to 

 17 or less in related forms. 



Order PLECTOGNATHIDA 

 Suborder Balistina 

 Family ALUTERIDAE 



By Loren p. Woods 



key to the species of aluteridae from the northern marshall islands 

 and adjoining regions 2' 



la. Pelvic spine present. 



2a. Pelvic spine moveable, dorsal spine not fitting into a groove when 

 depressed. 

 3a. First dorsal spine inserted over middle of eye, 2 rows of small tubercles 

 on its anterior surface, row of long, strong spines pointing outward, 

 curving downward on its posterolateral edges, 6 to 17 spines per 

 row, spines placed alternately; pelvic spine prominent with radiating 

 spinules; scales of body with 3 to 5 retrorse spines, middle spine 

 largest, those of caudal peduncle long, slender, antrorse. Color 

 of head and body light reddish brown to dark blackish brown; 

 sides of body plain or with numerous dark reddish brown irregular 

 lengthwise fine lines; tip of snout and lips black. Dorsal rays 

 1,30 to 34, anal 27 to 30, pectoral II to 14, gill rakers 20 to 23. 



25 Characters used in separating genera are modified after Fraser-Brunner (Ann. Mag. Nat. Hist., ser. 

 11, vol. 8, pp. 177-181, 1941). 



