parasites of offshore big game fishes of puerto rico - Uprm

MONOGENEA (GILLWORMS)
Tristomella lintoni (Price) - This species was reported from the gills of a
skipjack tuna caught off Woods Hole, Massachusetts, USA. It was described
from a single immature specimen which was not in good condition (USNPC
4878). Despite the occurrence of this worm and "Capsala laevis" in checklists
of western Atlantic skipjack tuna, we find no valid records of capsalids on this
fish in our area. The specimen described by Price (1960) was probably then
result of accidental infection and its status must remain uncertain.
Tristomella onchidiocotyle (Setti) - MacCallum collected an immature
capsalid in the gills of a "Thunnus thunnus-horse mackerel" (=bluefin tuna)
from Woods Hole, Massachusetts, USA (USNPC 35644). Price (1939) des-
cribed this worm as a new species Capsala maccallumi, suggested that it was
probably identical to C. onchidiocotyle, but listed the host as "little tunny" with-
out explanation. The haptor of this worm extends beyond the body outline.
Testes are numerous and extend beyond the field between the ceca. The anchors
have a distinct hook on the end. It occurred on bluefin tuna in the Mediterranean
and bigeye tuna off west Africa, probably on bluefin tuna off the Atlantic coast
of the USA and throughout the Atlantic. This parasite occurs on the gills and
is 2.6 mm long. It is probably genus (Thunnus) and tribe specific. This worm
needs to be redescribed and more collections are needed in the western Atlantic
to resolve the mystery of its distribution.
CESTODA (TAPEWORMS)
Tapeworms or cestodes form a large class of the flatworms or
platyhelminths. The common name comes from the long series of body
segments which resemble a tape measure. Most adult tapeworms look like long,
flat cooked noodles. Most larval forms look like the tiny pieces of noodle that
stick in the colander. A giant, broad tapeworm that lives in the body cavity of
freshwater fishes in Europe is apparently routinely eaten by humans who mistake
it for parts of the fish! Tapeworms can reduce growth and affect reproductive
success of fishes. Some that infect humans occur as immature or larval forms
in fishes. A small-boat fishery for tunas on the northwest coast of Puerto Rico
was closed by the government because of reports of "wormy" flesh in these food
fishes. When we were contacted to examine these parasites, we found that they
were larval tapeworms, and recommended that the fishery be immediately
reopened. We knew that previous experimental attempts to infect mammals with
similar larvae failed because the parasites mature only in sharks and rays. The
fishery was quickly reopened, averting major losses to local fishermen. We
occasionally receive similar cases of wormy filets from individuals. People do
not like seeing larval tapeworms moving around in the flesh of their fish, but
those in Puerto Rican fishes are relatively harmless (particularly when cooked).
More than 5000 species of tapeworms are known. Adults range from less
than a millimeter to more than 30 meters in length. Tapeworms usually consist
of a chain of segments (proglottids) each with a set of female and male
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