Beyond that, however, comparison of the data in 

 Table 2 with those presented by Robins (1974) for 

 white marlin from the eastern Atlantic reveals dif- 

 ferences only in four features: the width at the sec- 

 ond anal fin (less in georgei), the orbit diameter (less 

 in georgei), the length of the 25th dorsal spine, a 

 measure of the posterior height of the fin (greater in 

 georgei), and the distance from the anus to anal fin 

 (greater in georgei). 



The discovery of georgei makes more complete 

 the transition between Tetrapturus albidus and T. 

 audax on the one hand, called marlins because of 

 their form and size, and the smaller species of spear- 

 fish, T . belone, T . angustirostris, and T. pfluegeri. 

 Structurally, and in reference to the dendrogram in 

 Robins and de Sylva (1960: Fig. 5), both pfluegeri 

 and georgei would fall between T. belone and T. 

 albidus. There is thus no clear division of the genus 

 and no basis for recognizing as distinct subgenera 

 Tetrapturus and Kajikia. 



The continued placement of albidus in Makaira by 

 Ovchinnikov (1970) is unexplained and naive. 

 Likewise Ovchinnikov's distribution of T. belone is 

 confused withpfluegeri, and his inclusion of georgei 

 as a synonym of belone is incorrect. 



Distribution. Tetrapturus georgei is positively 

 known only from the specimens reported on here 

 from Sicily, the Strait of Gibraltar, and the adjacent 

 Atlantic Ocean off southern Portugal. Its occur- 

 rence at Madeira is inferred by application of the 

 name georgei. Obviously this species can be ex- 

 pected to range widely in the eastern and perhaps 

 central north Atlantic. Many of the records of Tet- 

 rapturus pfluegeri from these regions may be of 

 georgei. Clarification of the central and eastern At- 

 lantic records of spearfish from Japanese data 

 (Ueyanagi et al., 1970) is of vital importance. The 

 larvae and juveniles and their areas of occurrence 

 are unknown. Data are too few to permit discussion 

 of seasonal or annual variation in occurrence beyond 

 the point that all istiophorids reaching Madeira and 

 the southern coasts of Portugal and Spain do so 

 during the warm months and that a movement south 

 and west during the cold season may be assumed. 



Hybridization. Hybrids in fishes are usually in- 

 termediate in characters most often used by sys- 

 tematists (i.e., fin-ray counts, body proportions) be- 

 cause these characters apparently are polygenic and 

 the genes pleiotropic. This has been frequently dis- 

 cussed but perhaps nowhere more clearly than by 

 Hubbs (1940:205-207; 1943). Whenever a rare 

 species occurs which is intermediate in its characters 



Figure 2. — Squamation of Tetrapturus georgei, patch 100 

 x 100 mm from right side below spinous dorsal fin. Draw- 

 ing by Charles D. Getter. 



between two more common species, there are a 

 priori grounds for believing it to be based on hybrids 

 between the two. Natural hybrids in fishes are most 

 common among freshwater species where man's al- 

 teration of the environment has resulted in break- 

 down of ecological barriers. Hybrids are rarer 

 among coastal fishes, rarer still in the stable envi- 

 ronment of the tropical reefs, and unknown among 

 truly oceanic fishes. Hybridization in a long estab- 

 lished pelagic family like the Istiophoridae would 

 seem to be highly unlikely. 



Two possible hybrid combinations were consid- 

 ered in analyzing the characters of georgei: 1) Tet- 

 rapturus albidus x T. belone, and 2) T. albidus x T. 

 pfluegeri. Analysis of Table 1 shows that T. georgei 

 is intermediate in several of its most diagnostic 

 characters between T. albidus and both pfluegeri 

 and belone, namely the position of the anus and the 

 diameter of its orbit. Its squamation is unique and 

 the shape of its dorsal- and anal-fin lobes are as in 

 albidus. Additional data for pfluegeri are available 

 in Robins and de Sylva (1960, 1963) for belone in 

 Robins and de Sylva (1963) and for albidus in Rob- 

 ins (1974). In the height of its first dorsal and anal 

 fins, georgei is as extreme as albidus. In short, no 

 good case can be made to consider georgei to be 

 based on hybrids. Also, available evidence on 



59 



