Leech-Like Parasites (Clitellata, Acanthobdellida) Infecting Native and Endemic Eastern Siberian Salmon Fishes

Irina A Kaygorodova,Elena V Dzyuba,Nikolay M Pronin

doi:10.1100/2012/652827

Irina A Kaygorodova, Elena V Dzyuba + Show 1 more

Open Access

https://doi.org/10.1100/2012/652827

Copy DOI

Abstract

Salmonoid fish bdellosis is caused by leech-like ectoparasites in the monogenetic order Acanthobdellida. Although Acanthobdella species have been known to infect several threatened species in Eurasia, little is known about their ecology and epidemiology. In this paper, we report on the mass affection (up to 70.7%) of fish in lower course of the Chechuj River, a right tributary of the Lena and provide information on finding Acanthobdella peledina on two of six salmonoid fish species inhabiting there: lenok and grayling. New and more specific data on morphological peculiarities and feeding strategy were obtained. The ratio of body length to width in studied acanthobdellid collection is significantly less than one provided for the A. livanowi and the rest A. peledina from other water systems of Eurasia. Biology and lifestyle of the parasite population are revealed for the first time.

Highlights

The Acanthobdellida, a group of annelid worms, comprises of parasites of fish, which are restricted to the extreme northern parts of the northern hemisphere
Our basic knowledge of morphology of the A. peledina goes back to Livanow’s monograph of 1905 [1] that was updated by the author in his publication in 1931 [2] in which this species was identified as an ancient hirudinean and close phylogenetic relationships between both the Hirudinea as well as the Oligochaeta were proposed [2, 3]
The “living relic” A. peledina occupies a transitional phylogenetic position between the oligochaetes and the leeches, as shown by morphological and life cycle investigations [4,5,6,7,8] and molecular phylogenetic analyses [9,10,11]. These archaic freshwater leech-like clitellates belonging to Acanthobdellida are semipermanent parasites, restricted almost exclusively to salmonoid fish

Summary

Introduction

The Acanthobdellida, a group of annelid worms, comprises of parasites of fish, which are restricted to the extreme northern parts of the northern hemisphere. The “living relic” A. peledina occupies a transitional phylogenetic position between the oligochaetes and the leeches, as shown by morphological and life cycle investigations [4,5,6,7,8] and molecular phylogenetic analyses [9,10,11]. These archaic freshwater leech-like clitellates belonging to Acanthobdellida are semipermanent parasites, restricted almost exclusively to salmonoid fish. Each new finding on A. peledina is important both for understanding poorly studied aspects of its life cycle and ecology, and for studying its role in the evolution of segmented worms as a whole

Material and Methods

Results

Salmoniformes

Discussion