On the Ecology and Distribution of the Parasitic Copepod Mytilicola Intestinalis Steuer

P Korringa

doi:10.1163/26660644-03801008

Abstract

Critical appraisal of the literature data on Mytilicola intestinalis, combined with personal experience in this field, led to formulation of answers on a series of questions re the ecology and distribution of the parasitic copepod Mytilicola intestinalis Steuer. It is confirmed that Mytilicola has been the causative agent in extensive mussel mortalities. The explosion of Mytilicola in several places on the coastlines of North Sea and Atlantic Ocean should be explained in terms of Mytilicola, being a new intruder in these waters. There is no ground for the view that a special set of ecological conditions saw to the explosive development of the autochthonous species Mytilicola intestinalis, normally existing in small numbers only. Mytilicola intestinalis has a wide ecological range in all phases of its life cycle. The number of hosts living in a given volume of water, together with the amount of flushing of that water, is the main factor governing the number of parasites per host. Since two individuals of opposite sex have to meet in the intestinal tract of one and the same host, some scattered pelagic larvae cannot easily lead to establishment of a new focus of infection. Stretches of coast devoid of mussels form an almost unsurmountable barrier against the natural spreading of this parasite. It is usually man, through his multiple activities, who should be held responsible for the invasion of mussel areas previously devoid of Mytilicola intestinalis.

Highlights

ANDREU, B., 1960: Un parasita del mejillón
Prior to 1950 very few scientific papers had been devoted to the parasitic copepod Mytilicola intestinalis Steuer
Stretches of coast devoid of mussels form an almost unsurmountable barrier against the natural spreading of this parasite. Through his multiple activities, who should be held responsible for the invasion of mussel areas previously devoid of Mytilicola intestinalis

Summary

Mytilicola intestinalis Steuer by

Prior to 1950 very few scientific papers had been devoted to the parasitic copepod Mytilicola intestinalis Steuer. Where thousands of mussels have been opened and cut up year after year for sanitary control purposes, as in Holland, it is incredible that Mytilicola would never have been observed during those practices had Mytilicola occurred there in even a low percentage of the mussels (KOHRINGA, 1951) It is true, that some marine organisms with an inconspicuously low level of population density may suddenly appear in incredible numbers, apparently because a given combination of environmental factors accidentely favoured their reproduction. The transplantation experiments described by MEYER-WAARDEN and MANN (1954b) demonstrate that any parasite-free mussels brought into the infested Jade estuary soon get their share of parasites, and their observation in Italy (1954a) that the local mussels in the Lago di Ganzirri (Sicily) did not become infested after introduction of a commercial consignment of Mytilicola-bearing mussels from La. Spezia is not at all an argument in favour of the epidemical nature of Mytilicola ’s mass-developments elsewhere. It start all over again from a limited parent stock at the beginning of the new growth season (KORRINGA and LAMBERT, 1951)

Without any doubt Mytilicola intestinalis’

It survived several severe winters in the Eastfrisian

Summary

Findings

Protecting British