1 
The activities of the Registry during 1975 reflected an increased interest 
in the cause and significance of neoplasia in invertebrate and cold-blooded 
vertebrate animals. As pointed out in the two previous activities reports 
(copies of which are still available) there are numerous proven and hypothe¬ 
sized benefits from studying neoplasms in lower animals including the dis¬ 
covery of: new carcinogens, indicators of carcinogens in the environment, 
vectors of cancer viruses, reservoirs of chemical carcinogens, multipliers 
of carcinogens in the food chain, models for the study of mechanisms of 
neoplastic transformation, sources of anti-cancer compounds, and models for 
screening the carcinogenicity and mutagenicity of new chemicals. Protection 
of animal populations from epizootic neoplasia and research spinoff in re¬ 
lated fields can be added to this list. 
SPECIMEN COLLECTION 
The specimen collection is the most important component of the Registry’s 
mission and we invite contributions of any material showing neoplasms or 
related diseases in cold-blooded vertebrates and invertebrates. The ma¬ 
terial will be processed as required and where applicable a set of micro¬ 
scope slides will be returned with the diagnosis. Almost all of the cases 
received add to the information on geographic and phylogenetic distribu¬ 
tion of these diseases and their manifestation within the organism. In ad¬ 
dition, many of the cases have special significance as they relate to one 
of the benefits mentioned above. Unfortunately a report such as this does 
not portray the total significance of each case, but in conjunction with 
the literature it will give one a fair estimation of where we stand. 
In 1975 the specimen collection increased by 305 accessions, which repre¬ 
sented a 62% increase over those received in 1974. The complete list of 
specimens with the diagnosis, name of contributor, and pertinent reference 
when applicable, is included in this report. Table I gives a breakdown of 
the major phylogenetic groups with the ratio of neoplastic to non-neoplas¬ 
tic lesions. The bulk of the specimens are bony fish and bivalve mollusks. 
Approximately two-thirds of the diagnosed material was neoplastic, but 
mollusca and arthropoda continue to be the only invertebrate phyla from 
which verifiable neoplasms are known. 
Among the accessions of special interest were 47 hagfish cases having 
hepatocellular, cholangiocellular, and/or islet cell adenomas and adeno¬ 
carcinomas. These cases, representing the only known neoplasms of this 
primitive vertebrate, were discovered in a Baltic Fjord by Sture Falkmer. 
Incidence decreased from 5.8% (liver lesions) and 0.5% (islet organ le¬ 
sions) in 1972 to 0.6% and 0.1% respectively in 1974. The cause has not 
been determined. 
Also of note were 102 cases from the soft-shell clam, Mya arenarla , pri¬ 
marily with germinomas and hematopoietic neoplasms. These animals were 
from an area where spillage of refined petroleum products has occurred. 
Incidence has averaged 4-5% in about 3,000 animals surveyed since 1971. 
Incidence of approximately 850 animals collected away from the oil spill 
site is 0.3-0.4%. 
