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to information received by me from the collector, Fil. lic. H.J. ÖSTERGREN, all the specimens
were quite active and emitted an intensely phosphorescent light. This faet, like the
circum-stance that a number of specimens were fourni in the uterus, decidedlv indicates that they had
not been swallowed by the fish as food, i. e. that they had not passed through the alimentary
canal, but it must be assumed that they penetrated actively into the fish, where they lived
on waste produets and, at least in the uterus, as parasites.
Curiously enough all the twenty-five specimens were found in a single specimen of the
above-mentioned fish, although no less than about a hundred specimens of the latter were
in-vestigated (according to information received from Fil. lic. ÖSTERGREN). As I have carefullv
investigated myself about sixty specimens of this Etmopterus species caught in Trondhjem
Fjord without finding a single specimen of Cypridina and Fil. lic. Ö. Nybelin has investigated
about 150 from the same fjord with a similar negative result, this habitat must perhaps be
regarded as a rare one, in spite of the curiously large number of specimens found in one fish.
— It ought perhaps to be pointed out that C. (V.) norvegica seems to be very rare in Trondhjem
Fjord: „Sparsim in sinu Nidarosiensi“ (G. 0. Sars, 1865). (Is it possible that all these
25 specimens are the offspring of one and the same fertilized female which have left the mother
after the latter had penetrated into the fish?)
I was unable to discover any morphological differences between free-living specimens
and the parasitic specimens, although they were subjected to a very minute examination.
There may be an inereased interest attached to this find because this is not the first
nor the only tilne that a C y pr id in id has been found under conditions that seem to indicate
a certain tendency to parasitism.
The first mention of a case of this sort in the literature is to be found in 0. G. Costa’s
work in 1847, p. 6. Here we find the following statement: ,,Dopo la pubblicazione délia Memoria . .
dissecando una Scorpaena scrofa, trovammo tutta la cavità addominale, o meglio il peritoneo
in ogni punto attaccato da questo ostracode parassito, ehe a primo sguardo presentavasi
come di glandolette bianche di cui pareva disseminato il cavo addominale. Noi potemmo
trarve 120 di tutte le grandezze, niuno uguagliando pero i precedent! ospitanti nell’ 0fisuro.
La quai causa rafferma essere propria una tale specie del Mediterraneo, e vivere abitualmente
parassita su i pesei.“
The latter find is mentioned in the same treatise, p. 1. Here we find that a Cypridinid,
presumably the same species as in Scorpaena scrofa, i. e. Cypridina mediterranea, was found
on the body of a Ophisurus ,,Noi trovammo nel corpo di un O f i s u r o1’.
The next find is mentioned by A. BRIAN in a short essay on parasitic Crustacea (1909).
In this we find that a number of specimens of Cypridina mediterranea (?) were found in ,,seni
e canali frontale“ of a fish Coryphaena hippurus. The length of these specimens was only 2,5 mm.,
which suggests that they were not sexually mature. With regard to this case the author writes
as foliows: „Questa specie d’o s t r a c o d e non è da ritenersi parassita per quanto trovata
su di un pesce. Esse vive liberamente e non si tratta qui che di un semplice caso di
commen-salismo.“ In other words this author considers this habitat quite an accidentai one, as I
did above.
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