Deposited at: Science College Museum, Tokyo Uni- 

 versity. 

 Catalog' No.: 4187. 

 Reported by: Shigeho Tanaka. 



Type locality: Sagami Bay, southern coast of cen- 

 tral Japan. 



Diagnosis: 



1. The snout is very short and the body deeply com- 



pressed. 



2. The first dorsal fin at the anterior lobe is nearly 



the same as the body depth, then being evenly 

 high posteriorly 



3. The second anal fin is situated anterior to the sec- 



ond dorsal fin. 



4. The pectoral fins are narrow and short. 



5. The anus is situated far anterior to the origin of 



the first anal fin. 



6. The number of first dorsal spines ranges from 46 



to 50. 



7. A paired gonad is asymmetrical and Y-shaped, 



the left lobe is much longer. 



Subjective synonymy: 



Tetrapturus illingworthi Jordan and Evermann, 



1926. 

 Tetrapturus kraussi Jordan and Evermann, 1926. 

 Tetrapturus brevirostris Fowler, 1928. 

 Psudohistiophorus angustirostris de Buen, 1950. 

 Psudohistiophorus illingworthi de Buen, 1950. 

 Tetrapturus indicus Deraniyagala, 1951. 



Artificial key to genus: The following key to the 

 species of Tetrapturus is based on Nakamura et al. 

 (1968), who constructed a key to all the species of the 

 Xiphiidae and Istiophoridae. 



a First dorsal fin is rather high at the anterior part, 

 being nearly at the same height to the posterior. 

 Anus situated far anterior to the origin of first 

 anal fin. Second anal fin situated anterior to the 

 second dorsal fin. 



b Pectoral fins narrow and short 



T. angustirostris Tanaka 



c Snout remarkably short 



T. belone Rafinesque 



b Pectoral fins broad and long 



T. pfluegeri Robins and de Sylva 



a First dorsal fin is slightly higher than, or nearly 

 the same as, body depth at the anterior part, then 

 gradually lowered. Anus situated just anterior of 

 the origin of first anal fin. Second anal fin and sec- 

 ond dorsal fin nearly opposite, 

 d Pectoral fins broad with rounded tip. Tip of 

 first dorsal fin and first anal fin roundish 



T. albidus Poey 



d„ Pectoral fins narrow with pointed tip. Tip of 



first dorsal fin and first anal fin pointed . 



T. audax (Philippi) 



1.22 Taxonomic status 



Recent morphometric studies on external 

 characters of T. angustirostris suggest that there may 

 be clinal or population variations in some of these 

 characters among specimens from different oceans. It 

 seems natural, therefore, to think it polytypic (see 

 1.31). 



1.23 Subspecies 

 None. 



1.24 Standard common names and ver- 

 nacular names 



1.3 Morphology 



1.31 External morphology 



Generalized: The billfishes are generally large and 

 elongate, and are usually characterized by a long pro- 

 jected spearlike snout (the snout is as long as 30% of 

 the eye-fork length or more, except for the shortbill 

 spearfish, which is the only species with an especially 

 short snout). The ventral fins are more or less 

 diminished. Other fins, especially the caudal fin, are 

 well developed. The form of the first dorsal fin varies 

 markedly according to the species. The vertebral 

 bones are peculiar in structure with well-developed 

 platelike neural and haemal spines and 

 characteristically extended anterior neural and 

 anterior haemal zygapophyses. The number of 

 vertebrae are 24 (12 + 12 or 11 + 13) (Ueyanagi, 

 1963b). 



The external morphology of T. angustirostris as 

 described by Nakamura et al. (1968) is as follows: 



ID, XLVII-L; IID, 6-7; IA, 12-15; HA, 6-7; P, 18 - 19; V, I, 

 2. Body elongate and very laterally compressed (body length 

 about 16.1-22.2 times body width). Body height remarkably low 

 (body length about 8.3-10.4 times body height). Snout short 

 (head length about 1.6 times upper jaw length), and round in 

 cross section. Body densely covered with slender, bony scales 

 whose tips are 3-5 cusped. Minute filelike teeth on both jaws and 

 palatine. Lateral line curved above pectoral fin and straight to 

 caudal portion. Head large (body length about 4.2-4.7 times 

 head length). Eyes moderate in size, without ridge over the or- 

 bit. Dorsal profile straight from snout to insertion of first dorsal 

 fin. Caudal fin deeply forked, both upper and lower lobes slight- 

 ly narrow in width. Two lateral keels on either side of caudal 

 peduncle. Pectoral fin somewhat low-situated (head length 

 about 1.6-2.3 times pectoral length), with pointed tip. First dor- 



41 



