The invasive cestode Triaenophorus crassus Forel, 1868 (Cestoda, Pseudophyllidea) in fish of the Saratov Reservoir

Abstract

The infestation of fish in the Saratov Reservoir with the cestode Triaenophorus crassus (Cestoda, Pseudophyllidea) was studied. The material was collected in 2009–2015 from the middle part of the reservoir; complete parasitological dissection of Neogobius melanostomus (Pallas) – 320 ind., Neogobius iljini (Vasiljeva et Vasiljev) – 146 ind., Proterorhinus marmoratus (Pallas) – 21 ind., and Esox lucius (Linnaeus) – 49 ind. was carried out. The plerocercoids of T. crassus were mainly found in the muscles of gobies, also alien to the Saratov Reservoir. The highest invasion rates (50%, 2.15 ind.) were registered in N. iljini, a second intermediate host of the cestode in the Saratov Reservoir. The parasite reaches maturity in pike, a definitive host. The high level of pike infection with the cestode (55.1%, 6.4 ind.) can be due the key role of gobies in pike feeding. The obtained results confirm the ongoing transformation of the system of food chains and the successful adaptation of T. crassus in the reservoir.

Keywords

• triaenophorus crassus
• cestode
• invasive species
• infection
• fish
• saratov reservoir