t i i m o o r . 'l'lit> Ic\sion wiis iiivirsivc. iLIrtt Irsd iilreidy pt.~~tbtr~~t~td tdirough
t,lle niitiitle niiisclc into t,he o v t q . 'I'liis tuniour, like the previous two
ciescrikwtl, rtwmbletl mc ire tl I P Iid(.rioc;ircin(,rna-like lesion of the vertebrate. ' 1' 0 dihte twelve such t umours Ititve 1)een fourid and Wolf makes
the following siiggestionu as t o possiblc aetiologics :
(1) a genetic! mutation, whirli had pro'luced a susceptible strain
of oystror ;
(2) infcctious agent, i s . virus, in oyster bed ;
(3) infectious agent, non-pthogeiiic urit il oysters have been made
suuceptible by genetic mutation.
Dinammi anti Wolf ( I !)74, in press) have reported multiple tumours in
the pericardial cavity of an Aiistralian Rock Oyster Crmsostrea commercialis, t~nd cwnsidcred the differential diagnosis in the following order :
(i) slow growing multicentrio benign neoplasm of Leydig cell origin ;
(ii) congenitid anomaly ; (iii) hyperplasia secondary to infection or
injury. Theso tiirnours were similar to those described earlier by Ryder
and Smith. Brown ~t al. (1!)73) reported an incidence of tumours in
' L 121 fi.eshwiLt,er fish cxamincd from the Fox River watershed (4.38%)
t ~ s conipurwt with 4ti3!j fish examined in Canada (1.03%). The FOX
River watershtd arises from underground streams, presumably from
Lake Superior, t ~ n d ww found to he i~ highly polluted system. The
effects of pollution runnot bv disregarded, as will be discussed later in
relation to vertebrate fish,
Pindly, t here is thc> txxtrornely interesting case of the coral in which
a markd loc4ized lesion W ~ L S seen (Fig. 8). 1)oes this represent a
neoplastic! rcvponsch or is i t merely u parasitic infection by Porites
compw.unci. anti f
'
. Iobata (Squires, 1965) ! It will be obvious from the foregoing tltut only i n the Australian Rock Oyster doeu one see a histological
pattern similar to thiit recorded in vertebrates. The mesenchymal
tuinours, if indeed thc1. V are turnours a t all, tLre interesting, since the
me.senchyma1 tnmour of vertebrate fish predominates over all other
types. This is in complete contradistinction to the higher mammals,
in which the epithcliul tamour is by far the iiiost common.
[rr. N E O P L A S ~ A IN FISH
WIicn reviewing the* progrcw of fish p~~thology irr this ocritury
Snieszlm ( I !)72) statotl that '' AIIYC)II(? (:xpecting to firid thiit there is u
wealth of piiblications on fix11 pat,hology inore than I00 years old will
1)e rliuu1)poiiitcd ", and with the cxcq~tion of u few caxw t h i H is trw.
This gives sonit' indication t lrat although I'irdiow wiLx t h c a J)Lt Irw of
CthllllllLr I"tt I~ol~ggy, t htn tlin~;ircv I)rowns i l s dwwi t)(*(I iti l t i ~ g:l't*iht hook
t,lle niitiitle niiisclc into t,he o v t q . 'I'liis tuniour, like the previous two
ciescrikwtl, rtwmbletl mc ire tl I P Iid(.rioc;ircin(,rna-like lesion of the vertebrate. ' 1' 0 dihte twelve such t umours Ititve 1)een fourid and Wolf makes
the following siiggestionu as t o possiblc aetiologics :
(1) a genetic! mutation, whirli had pro'luced a susceptible strain
of oystror ;
(2) infcctious agent, i s . virus, in oyster bed ;
(3) infectious agent, non-pthogeiiic urit il oysters have been made
suuceptible by genetic mutation.
Dinammi anti Wolf ( I !)74, in press) have reported multiple tumours in
the pericardial cavity of an Aiistralian Rock Oyster Crmsostrea commercialis, t~nd cwnsidcred the differential diagnosis in the following order :
(i) slow growing multicentrio benign neoplasm of Leydig cell origin ;
(ii) congenitid anomaly ; (iii) hyperplasia secondary to infection or
injury. Theso tiirnours were similar to those described earlier by Ryder
and Smith. Brown ~t al. (1!)73) reported an incidence of tumours in
' L 121 fi.eshwiLt,er fish cxamincd from the Fox River watershed (4.38%)
t ~ s conipurwt with 4ti3!j fish examined in Canada (1.03%). The FOX
River watershtd arises from underground streams, presumably from
Lake Superior, t ~ n d ww found to he i~ highly polluted system. The
effects of pollution runnot bv disregarded, as will be discussed later in
relation to vertebrate fish,
Pindly, t here is thc> txxtrornely interesting case of the coral in which
a markd loc4ized lesion W ~ L S seen (Fig. 8). 1)oes this represent a
neoplastic! rcvponsch or is i t merely u parasitic infection by Porites
compw.unci. anti f
'
. Iobata (Squires, 1965) ! It will be obvious from the foregoing tltut only i n the Australian Rock Oyster doeu one see a histological
pattern similar to thiit recorded in vertebrates. The mesenchymal
tuinours, if indeed thc1. V are turnours a t all, tLre interesting, since the
me.senchyma1 tnmour of vertebrate fish predominates over all other
types. This is in complete contradistinction to the higher mammals,
in which the epithcliul tamour is by far the iiiost common.
[rr. N E O P L A S ~ A IN FISH
WIicn reviewing the* progrcw of fish p~~thology irr this ocritury
Snieszlm ( I !)72) statotl that '' AIIYC)II(? (:xpecting to firid thiit there is u
wealth of piiblications on fix11 pat,hology inore than I00 years old will
1)e rliuu1)poiiitcd ", and with the cxcq~tion of u few caxw t h i H is trw.
This gives sonit' indication t lrat although I'irdiow wiLx t h c a J)Lt Irw of
CthllllllLr I"tt I~ol~ggy, t htn tlin~;ircv I)rowns i l s dwwi t)(*(I iti l t i ~ g:l't*iht hook