poorly known species, see Robins (1974b). Nakamura, 

 Iwai, and Matsubara (1968) refer to spearfish being 

 taken "from the northeast and north-central Atlan- 

 tic." However, their illustrations (Fig. 18) do not 

 appear to be of T. belone or of T. pfluegeri; they may 

 represent T. georgei or even an undescribed species. 



Tetrapturus belone belongs ecologically to the 

 ichthyofauna of the oceanic epipelagic (Parin, 1968). 

 It evidently completes its entire life history in the 

 open sea. However, because of the steepness of the 

 continental shelf and the proximity to shore of oceanic 

 waters in the Mediterranean, this spearfish could 

 come very close to land. 



Vertical distribution is unknown. It is usually taken 

 at the surface by harpoon and several types of nets. In 

 the Gulf of Castellammare (Sicily) and near the towns 

 of Torretta Granitola and Marinella, a few are caught 

 in tuna traps (Robins and de Sylva, 1963:96). It is oc- 

 casionally caught by using flag lines and drifted 

 handlines. Like other billfish, it probably feeds in the 

 upper 200 m (epipelagic), generally above and within 

 the thermocline. 



2.2 Differential Distribution 



2.21 Spawn, larvae, and juveniles 



Spawning areas are unknown. Lo Bianco (1903, 

 1909), Sparta (1953, 1961), Padoa (1956), and 

 Cavaliere (1962) reported larval stages of T. belone 

 from the Strait of Messina. 



The larvae reported by Lo Bianco (1903, 1909) can- 

 not be identified with certainty, in spite of the state- 

 ment by Robins and de Sylva (1963:95-96), which 

 notes that one larva (illustrated by Padoa, 1956:514- 

 516, pi. 36, fig. 7) "is clearly an istiophorid and, . . . 

 probably . . . T. belone." It seems probable that the 

 larvae depicted by Sparta (1961) may well be those of 

 T. belone because the adults of other istiophorids are 

 not common near the Strait of Messina. 



As mentioned earlier, two juveniles (356 mm and 

 597 mm) were taken from Haifa, Israel, and off 

 Lebanon, respectively. These represent the only two 

 early juvenile specimens of T. belone which can 

 definitely be identified. Rafinesque's (1810) type 

 specimen, a juvenile, was from Sicily but this does not 

 indicate that the specimen was spawned nearby. A 

 juvenile of 37 mm was taken in the Strait of Messina 

 along the beach at Ganzirri (Cavaliere, 1962:Fig. 2), 

 which agrees with the 597-mm specimen collected 

 from Lebanon except for the lower dorsal fin and the 

 lack of spots on the anterior rays. A juvenile billfish 

 (BMNH) from Malta is figured by de Sylva and 

 Ueyanagi (see footnote 3); however, is it unlikely that 

 this is the young of T. belone because of the peculiar, 

 extensive markings on the dorsal fin, which are 

 limited to a few spots on the anterior rays in the larger 

 juveniles of T. belone from Israel and Lebanon. Thus, 

 nursery grounds for juveniles of T. belone are known 

 only from the eastern Mediterranean Sea. 



2.22 Distribution of adults 



Adults of T. belone are most common in the central 

 Mediterranean about the Strait of Messina. Such in- 

 ferences are based solely upon the catch of commer- 

 cial fishermen, usually using harpoons, who are con- 

 centrated in this area. However, commercial fishing 

 using the same method occurs throughout the 

 Mediterranean for broadbill swordfish, Xiphias 

 gladius Linnaeus, and it could be expected that T. 

 belone would be collected elsewhere if it were com- 

 mon. There are no data on seasonal and annual 

 variations in abundance or availability. Sparta (1961) 

 noted that spearfish occurred in the Strait of Messina 

 in August and September, and were rare in October 

 and November, with some examples being taken dur- 

 ing the winter. He noted that they preferred the upper 

 waters of the Strait of Messina, which may well be 

 associated with upwelling and the consequent concen- 

 tration of food in these upper waters. 



2.3 Determinants of Distribution Changes 



As an inhabitant of the oceanic epipelagic, T. be- 

 lone is a stenotopic species whose habitat at all stages 

 of its life history is characterized by narrow geographi- 

 cal and seasonal variation in temperature, salinity, 

 and other physicochemical parameters. Like other 

 billfishes, it is typically a clear-water species requiring 

 high-transparency waters for its feeding (which is 

 largely visual. Robins and de Sylva (1963:97-98) pos- 

 tulated that the hypersaline waters and associated 

 changes in temperature and dissolved oxygen of the 

 eastern Mediterranean, especially the Levantine Ba- 

 sin, probably were influential in excluding T. belone 

 from the eastern Mediterranean. This may be true for 

 adults, although it does not apply to juveniles in- 

 asmuch as three are now reported herein from Israel 

 and Lebanon. 



Its food habits are poorly known. Probably it feeds 

 upon clupeoids and sauries, whose distribution is 

 closely determined by oceanographic conditions. 

 Thus, changes, either natural or man-made, should be 

 expected to affect the distribution of T. belone. 

 Organisms concentrated at or just above the ther- 

 mocline (de Sylva, 1962; de Sylva and Davis, 1963) 

 should be expected to concentrate T. belone for 

 feeding purposes (Hela and Laevastu, 1970). 



Presumably, drastic changes in the habitat, such as 

 from local freshwater runoff or pollutants, would 

 affect the distribution of this stenotopic species at all 

 stages of its life history. 



2.4 Hybridization 



No natural hybrids of this species are known. 

 Popular speculation contends that all billfish 

 hybridize, but there is no scientific evidence to sub- 

 stantiate this. 



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