The relationship between Branchiobdella spec. (Annelida, Oligochaeta) and its host, the noble crayfish (Astacus astacus L.)
Archiv für Hydrobiologie Volume 144 Number 3 (1999), p. 357 - 369
published: Mar 5, 1999
ArtNo. ESP141014403009, Price: 29.00 €
Oligochaetes of the genus Branchiobdella live on freshwater crayfish. For a long time they were regarded as parasites. The current consensus is that most species are commensals or perhaps facultative parasites. In the northern Fichtelgebirge, northeastern Bavaria, the local branchiobdellids were identified as Branchiobdella parasita (Braun 1805) Henle 1835. The abundance dynamics of the branchiobdellids are discussed in relation to their different density of infestation in separate noble crayfish populations. Chemical parameters of the water were analysed as one important factor. Another aspect was the preference of the branchiobdellids of special groups of host's and of crayfish's body regions. It was shown that they prefer larger crayfish stages. Analyses of the contents of the digestive tube verified that Branchiobdella parasita subsists on the epizoic flora and fauna on the crayfish and on plankton organisms. The crayfish is essential for the reproductive process of the branchiobdellids. For the adults the host merely serves to carry the worms and to offer an area for feeding on the abundant detritus and epizoic flora and fauna sticking to the crustacean surface.