36
CARL J. SINDERMANN
despite the fact that the hereditary factors involved were usually
complex.
Probably the most thorough studies have been made of the genetics
of pigmented tumors (Gordon, 1948, 1950). Neoplastic growths in
which pigmented cells play a dominant role are found in many animals,
and such neoplasms can be among the most malignant tumors known.
Among fishes, neoplasms developing from melanophores are the
commonest type of pigment-cell tumor, whereas tumors arising from
other chromatophores are rare. For example, Gordon (1948) founcl
melanotic tumors in marine or fresh-water representatives of 11 orders
of elasmobranchs and teleosts. Takahashi (1929, 1934) in a 13-year
survey of many types of tumors in 100 000 fish from the Sea of Japan
found three melanomas, one guanophoroma and one allophoroma.
Schmey (1911) reported a xanthoma from a single European shark
and Smith (1934) an erythrophoroma in an American winter flounder.
Epidermoid carcinomas have been reported from several species of
marine fishes. Johnstone (1924a) reported an instance in whiting,
Williams (1929) a case in pollock. and Beatti (1916) several examples
in drum. Odontomas have been reported in a croaker, Micopogon
opercularis, from South America (Roffo, 1925), and a haddock from
the Grand Bank (Thomas, 1926). Mesenchymal tumors have been
found in cod by Johnstone (1920, 1924b, 1926) and Williams (or). cit.).
Osteomas of the vertebrae were observed frequently in the red tai,
Pagrosomus mrrjor, a Japanese food fish, by Takahashi (1929). Nervesheath tumors (neurilemmomas) are frequent in the snappers
(Lutianidae). Luck6 (1942) estimated that up to 1% of the snappers
found in Tortugas waters had such tumors, and were called " cancer
fish " by fishermen. Thomas (1931), Schlumberger and Luck6 (1948),
and Luck6 and Schluniberger (1949) thoroughly reviewed the literature
on tumors in fishes and found that more than 120 species were involved.
On the basis of their review, the authors concluded that all the major
varieties of tumors that occur in mammals and birds occur in coldblooded vertebrates.
Goiter (thyroid hyperplasia) has been reported frequently from
fresh-water hatcheries (see, for example, Gaylord and Marsh, 1914), but
occurs only rarely in marine fishes held in aquaria. Schlumberger
(1955) observed goiter in a number of pilotfish, ErheiLeis naucrates L.,
held in the Philadelphia Aquarium for long periods. Other species
held in the same low-iodine water did not develop goiter, suggesting
species variability in metabolic need for iodine. Schlumberger observed
that the few reported examples of thyroid tumors in marine fishes
usually occurred in those kept in aquaria for long periods. Such
CARL J. SINDERMANN
despite the fact that the hereditary factors involved were usually
complex.
Probably the most thorough studies have been made of the genetics
of pigmented tumors (Gordon, 1948, 1950). Neoplastic growths in
which pigmented cells play a dominant role are found in many animals,
and such neoplasms can be among the most malignant tumors known.
Among fishes, neoplasms developing from melanophores are the
commonest type of pigment-cell tumor, whereas tumors arising from
other chromatophores are rare. For example, Gordon (1948) founcl
melanotic tumors in marine or fresh-water representatives of 11 orders
of elasmobranchs and teleosts. Takahashi (1929, 1934) in a 13-year
survey of many types of tumors in 100 000 fish from the Sea of Japan
found three melanomas, one guanophoroma and one allophoroma.
Schmey (1911) reported a xanthoma from a single European shark
and Smith (1934) an erythrophoroma in an American winter flounder.
Epidermoid carcinomas have been reported from several species of
marine fishes. Johnstone (1924a) reported an instance in whiting,
Williams (1929) a case in pollock. and Beatti (1916) several examples
in drum. Odontomas have been reported in a croaker, Micopogon
opercularis, from South America (Roffo, 1925), and a haddock from
the Grand Bank (Thomas, 1926). Mesenchymal tumors have been
found in cod by Johnstone (1920, 1924b, 1926) and Williams (or). cit.).
Osteomas of the vertebrae were observed frequently in the red tai,
Pagrosomus mrrjor, a Japanese food fish, by Takahashi (1929). Nervesheath tumors (neurilemmomas) are frequent in the snappers
(Lutianidae). Luck6 (1942) estimated that up to 1% of the snappers
found in Tortugas waters had such tumors, and were called " cancer
fish " by fishermen. Thomas (1931), Schlumberger and Luck6 (1948),
and Luck6 and Schluniberger (1949) thoroughly reviewed the literature
on tumors in fishes and found that more than 120 species were involved.
On the basis of their review, the authors concluded that all the major
varieties of tumors that occur in mammals and birds occur in coldblooded vertebrates.
Goiter (thyroid hyperplasia) has been reported frequently from
fresh-water hatcheries (see, for example, Gaylord and Marsh, 1914), but
occurs only rarely in marine fishes held in aquaria. Schlumberger
(1955) observed goiter in a number of pilotfish, ErheiLeis naucrates L.,
held in the Philadelphia Aquarium for long periods. Other species
held in the same low-iodine water did not develop goiter, suggesting
species variability in metabolic need for iodine. Schlumberger observed
that the few reported examples of thyroid tumors in marine fishes
usually occurred in those kept in aquaria for long periods. Such