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Alfred Ramsch, in his work of 1906, p. 384, rejects O. G. Costa’s assumption that wo
have to deal with parasitism in the case quoted above, put forward by O. G. COSTA*. He points
out that he had himself often corne across different forms of large Ostracods in Pagellus
both beneath the gill-cover and in the stomach; all the specimens so found were, however,
dead. He writes 1. c. : „Sie dienen den Fischen zur Nahrung und gelangen mit dem Atemwasser
an die Kiemen oder finden sich gelegentlich im Darmtraktus. Ihr angebliches Vorkommen
in der Abdominalhöhle möchte ich wohl als eine zufällige Erscheinung auffassen.“
This idea of A. Ramsch’s seems to be incorrect. It is true that O. G. Costa does not eive
any information as to whether the specimens found by him were alive or not at the time they
were caught, but all the evidence is in favour of their being parasitic specimens. Of course
this does not prevent 0. G. Costa’s theory that we are concerned with an exclusively
parasitic species from being incorrect.
From tbe cases put forward above one may perhaps draw the conclusion that within
the sub-genus Vargula there exists a certain „tendency“ towards a parasitic life. One may
perhaps say that it is the first groping attempts towards the carrying out of this tendency that
have been just brought to our notice.
It may be objected here that the word „parasitism“ ought not to be used for these cases. This
form of life ought rather perhaps to be called „commensalism“, as has already been done by A. BRIAN.
As a matter of faet we are probably dealing with a case which is on the boundary between these two
phenomena; both commensalism and real parasitism certainly exist; the question as to which
term is to be used before the problem has been investigated more closely is of minor importance.
If we try to détermine this species according to the scherne of the genus Cypridina given
by G. W. Müller, 1912, p. 10, we find as follows: The furca has nine claws, the third of which
is more than half the length of the second; the rostral incisur of the shell is well developed; the
length of the shell is less than 4 mm.; the upper lip has two large tusk-like processes — „Mit
2 hauerartigen Fortsätzen hinter den anderen Drüsenmündungen“; the second and fourth
furcal claws are joined to the lamina. — It is, however, not Cypridina norvegica we arrive at —
as, on account of the incomplete description of this species, it could not be included in this
examination scherne — but an antarctic species, Cypridina antarctica, G. W’. MÜLLER.
A close investigation of the description of the last-mentioned species — G. W. MÜLLER,
1908, p. 84 — shows that we are dealing with a form closely allied to C. ( Vargula) norvegica.
In order to be able to imdertake a more detailed comparison between these two forms I wrote
to Professor G. W. Müller, who was kind enough to send me a sexually mature female of the
antarctic form and it is on this material that the supplementary description given below is based.
Habitat: — Coast of Norway:
Lofoten Islands: 1 mature male, 2 mature females and 3 juvenes; coli, imknown;
R. M. S. 155. Skarnsund, Trondhjem Fjord; in a specimen of Etmopterus spinax (LINNÉ):
5 mature males, 12 mature females and 8 juvenes; coll. H.i. ÖSTERGREN; H. M. S. 156 and 157.
* „Vollkommen im Irrthum ist jedoch Costa, wenn or behauptet, daß Cypridina mediterranea parasitisch in
Fischen lebe.“
Zoloog. bidrag, Uppsala. Snppl.-Bd. I. ßi
Relation to
’. (V.) antarctica.
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