678' 



Cancer Research 



specie* 



Butterfly fish P/otox pinn^us 

 Scabbard fish L*pid«^ sp. 

 Butterfly 6sh Ptatax pinnaius 

 Pike Esox lucius 

 Codfish Caius wtwkma 

 Codfish Gadus morkma 

 Pike £f«s Indus 

 Flounder Psett^ ma$ctiea 

 C*rp Cyprinus carpia 

 Codfish Gadus morhiut 

 Croaker Pogomias ekromis 

 Red Tai Pagrosemus major (6) 

 Red Tai Pagrosomms major (2) 

 Codfish Gadus morkua 

 Coalfish Tharaira chaUopamtna (8) 

 Flatfish PoMUekUuias dhacous 

 Red Tai Pagro$omms wtajor (102) 

 Rock fish Sebastodes intrmls 

 Speckled trout Saivdimiu /oiUimcUs 

 Cat shark ScyUunhinus cankula 

 Red Tai Pagrosomui major 



Aogelfish Chaetadipterus fabtr (4) 



Aogclfish Ckaetodipitrus fabtr 



File fish Atuiera sckoepfi 



Taslb II: OsTvoMA 

 SiU 



Neural and haemal spines 



Dorsal fin rays 



Vertebral spines 



Dental plate 



Superior maxilla 



Intervertebral disc 



Vertebra 



Vertebral spines 



Skull bones 



Vertebrae 



Two vertebrae 



Mandible, haemal spines 



Haemal spines 



Pre- maxilla 



Dorsal fin spines 



Vertebral spine 



Haemal spines 



Dorsal fin 



Fin rays 



Skin 



Haemal spines 



First haemal spine 



Shoulder girdle 



First interneural spine 



Author 

 BeU, 1793 

 Gervais. 1875 

 Gervais, 1875 

 Bland-Sutton, 1885 

 Bland-Sutton, 1885 

 Bland-Sutton, 1885 

 Plehn, 1906 

 Schroeders, 1908 

 Fiebiger, 1909c 

 Williamson, 1913 

 Beatti, 1916 

 Kazama, 1924 

 Sagawa, 1925 

 Williams, 1929 

 Takahashi, 1929 

 Takahashi, 1929 

 Takahashi, 1929 

 Takahashi, 1929 

 Thomas, 1932b 

 Thomas, 1933b 

 Luck6 & Schlumberger 



(not published) 

 Luck6 & Schlumberger 



(not published) 

 Luck6 & Schlumberger 



(not published) 

 Luck£ & Schlumberger 



(not published) 



In considering the etiology of these tumors the 

 following characteristics must be taken into ac- 

 count: their frecjuent occurrence in a particular spe- 

 cies, the predominance of the tumors in the spines 

 of the sixth to eighth caudal vertebrae, and the 

 predilection of the tumors for fishes over 20 cm. in 

 length. A traumatic origin, as suggested by Taka- 

 hashi, and Kazama (96) does not adequately ex- 

 plain all these features of the neoplasm. An eluci- 

 dation of the problem must await study of the tumor 

 in the living animal. 



Chabanaud (27) has described a localized fusi- 

 form hypertrophy characteristic of certain spines of 

 the dorsal fin in several species of fishes — Corvina 

 clavigera, C. nigrita, and Sciaenoides perarmatus. 

 The enlargement of the spines was absent in very 

 young fish, but became manifest with increasing 

 age. The author concluded that these hypertrophies 

 Here not accidental, but might be "integrated with 

 the metabolism of the species." 



Dr. L. P. Schultz, ichthyologist of the National 

 Museum in Washington, called our attention to 

 similar changes in the angelfish Chaetodiptcrus 

 jaber. In old individuals of this species a localized 

 hjrpertrophy of the distal portion of the first inter- 

 haemal m^ tends to develop (Figs. 29 and 30). 

 The Milargement may become massive, in some in- 

 stances measuring as much as 4.5 x 3 z 2.5 cm. 

 Histologic examination revealed that the tumor con- 



sists of cancellous bone and concentrically arranged 

 bands of more condensed osseous tissue (Fig. 31). 

 A similar laminated structure is found in the otoliths 

 of fishes, where it is believed to result from periodic 

 (seasonal) fluctuations in the rate of growth. The 

 adipose tissue that had filled the marrow cavity was 

 still recognizable in some regions, but elsewhere had 

 almost disappeared. This overgrowth of bone prob- 

 ably represents a hyperostosis, rather than an 

 osteoma. 



Reports of the sporadic occurrence of osteomas in 

 various species of fishes are not uncommon. The 

 tumors are usually found in the fin rays and verte- 

 bral spines, though the maxillae have been affected 

 twice, and Fiebiger (49) reports an osteoma the size 

 of a child's fist that arose from the frontal bone of 

 a 900-gram carp Cyprinus carpio. A sagittal section 

 of the head revealed that much of the cranial cavity 

 had been obliterated by the growth. Histologically 

 the tumor consisted of bone and cartilage that in its 

 arrangement resembled normal endochondral bone 

 formation. 



The collection of fishes in the National Museum 

 contains the bones of an angelfish ChaetoiUptcrus 

 faber found in a Florida Indian kitchen-midden. 

 Several of the .spines bear symmetrical hyperostoses, 

 and an irregular bony overgrowth which may be 

 classified as an osteoma b present on one of the 

 bones (cleithrum) of the shoulder girdle (Fig. 32). 



