Population dynamics of alien gammarid species in the River Odra estuary

Abstract

During the period of 1988-2000, three alien gammarid species, i.e. Gammarus tigrinus Sexton, 1939, Pontogammarus robustoides G. O. Sars, 1894, and Dikerogammarus haemobaphes (Eichwald, 1841 were recorded in the Odra estuary. This study, the first record of G. tigrinus and P. robustoides in Poland, focuses on the distribution, abundance, and biomass as well as on population structure of the three new species found in the coastal zone of the estuary. G. tigrinus and P. robustoides were first sampled in the Szczecin Lagoon (mid-part of the estuary) in 1988. The densities of both species were high from the time they were first recorded and exceeded 10 000 ind. m )2 , while the biomass was 25 and 140 g m )2 , respectively. G. tigrinus occurred at higher densities in northern and eastern parts of the Lagoon, while P. robustoides was particularly abundant in the south-eastern part, most heavily affected by River Odra discharge. In 1999, the third gammarid, D. haemobaphes, was recorded in the southern part of the estuary. Both in 1999 and 2000, the species was found in qualitative samples (dredge collections of Dreissena polymorpha) taken from the western branch of the river. As estimated from quantitative samples, densities and biomass in the eastern branch were rather low and did not exceed 150 ind. m )2 and 2.7 g m )2 , respectively. The Szczecin Lagoon population of G. tigrinus produces at least two generations within a year: a summer one and an overwintering one. The latter is dominated by older and larger specimens. The species may reproduce in the Lagoon from April until November.

Species Composition and Distribution of Invasive Ponto‐Caspian Amphipods in the Off‐Channel Microhabitats of a Temperate, Lowland Dam Reservoir

“…All these species prefer similar substratum types: macrophytes and hard bottom (JAROCKI and DEMIANOWICZ, 1931;JAŻDŻEWSKI, 1975;MUSKÓ, 1989MUSKÓ, , 1993MUSKÓ, , 2000BIJ DE VAATE et al, 2002). Furthermore, they are often associated with D. polymorpha beds (WAWRZYNIAK-WYDROWSKA and GRUSZKA, 2005;BIJ DE VAATE et al, 2002;JAŻDŻEWSKI and KONOPACKA, 2000;NALEPA et al, 2001;RICCIARDI 2004, 2005) present at the offshore sites D and F in our study area. Mussel beds provide gammarids with a shelter against predators as well as a source of food, including faeces, pseudofaeces and benthic organisms living among mussels (KARATAYEV et al, 2002).…”

Abiotic factors affecting habitat selection by two invasive gammarids Dikerogammarus villosus and Pontogammarus robustoides

“…This difference between the species is surprising, considering that D. villosus is regarded as more associated with running waters (Bij de Vaate et al, 2002) than P. robustoides. Perhaps the adaptations of P. robustoides to commonly occupied sandy areas (Wawrzyniak-Wydrowska & Gruszka, 2005;_ Zytkowicz et al, 2008), which are poorly sheltered and exposed to wave actions, allowed it to counteract the water flow in our experiment. In a field study, D. villosus was found to be the least rheotolerant compared to D. haemobaphes and D. bispinosus and the most associated with structured habitats offering protection against flow (Borza et al, 2017).…”

“…Thus, this species appears to be better adapted to regulate its thermal conditions than D. villosus. Extreme shifts in temperature are usually found in shallow, unsheltered bottoms often inhabited by P. robustoides (Wawrzyniak-Wydrowska & Gruszka, 2005;_ Zytkowicz et al, 2008), whereas D. villosus lives in deeper waters (Kley & Maier, 2005; own observations in the sampling area) and/or on stony bottoms (Kley et al, 2009;Boets et al, 2010) where temperature regimes may be more constant. The effect of season (independent of acclimation) on thermal behaviour has also been observed in crabs (Cuculescu et al, 1998) and crayfish (Layne et al, 1985), but not in an isopod Asellus aquaticus, varying its thermal behaviour only in response to acclimation temperature (Lagerspetz & Bowler, 1993), like D. villosus in our study.…”

The impact of zebra mussel (Dreissena polymorpha) periostracum and biofilm cues on habitat selection by a Ponto-Caspian amphipod Dikerogammarus haemobaphes

“…Nevertheless, several species of Ponto-Caspian gammarids, such as C. ischnus, D. villosus and D. haemobaphes have been found in great densities among zebra mussels, which can help them colonize new areas (Devin et al, 2003;Gonzalez & Burkart, 2004;Wawrzyniak-Wydrowska & Gruszka, 2005;_ Zytkowicz et al, 2008). They exhibit apparent affinity for habitats formed by zebra mussels and select them preferentially in the presence of other substrata.…”