Habitat preferences of Ukrainian brook lamprey Eudontomyzon mariae ammocoetes in the lowland rivers of Central Europe

Abstract

The pattern of microhabitat preferences of Ukrainian brook lamprey Eudontomyzon mariae ammocoetes was examined in two rivers of central Poland: the Pilica River (the Vistula River basin) and the Grabia River (the Odra River basin). A comparison of abiotic factors of the rivers revealed differences in water speed and principal components: PC1 (determining gradient from decreasing medium sand to the increasing share of three fractions of gravel), PC2 (a gradient from the declining share of very coarse and coarse sand fractions to the growing content of fine sand) and PC3 (correlated with an increasing proportion of silt). The sites did not differ significantly in terms of water depth. Relative abundance and frequency of ammocoete occurrence in the Grabia River were higher than in the Pilica River. Only speed, PC1 and PC2 made a significant contribution to the prediction of larval occurrence. Eudontomyzon mariae larvae preferred substrata with a reduced amount of medium sand and increased content of gravel (PC1) as well as with a lower content of coarse sand and higher proportion of fine-grained sand (PC2). The ammocoetes also preferred areas with a water speed of 0·2 m s(-1) but avoided speeds ≥ 0·6 m s(-1). The abundance of E. mariae was affected by water speed, as well as by all PCs. The mean ± s.e. optimal current speed was 0·265 ± 0·007 m s(-1), while abundance decreased with increasing amounts of gravel (PC1) and increased with increasing amounts of fine sand and silt in the bottom substratum (PC2 and PC3). Comparison of ammocoete microhabitat use in the Pilica and Grabia Rivers showed the lack of differences in distribution in the preferred values of current speed, PC1 and PC2.

The effects of brown trout (Salmo trutta morpha fario) on habitat selection by larval Fire Salamanders (Salamandra salamandra): a predator-avoidance strategy

“…Habitat selection was assessed using Jacobs' index (index D), which is frequently used in habitat selection studies (e.g. Kauhala and Auttila 2010;Jażdżewski et al 2016). Jacobs' index is independent of the relative abundance of each habitat available to the animals, and is calculated according to the following formula:…”

Brook lampreys of life: towards holistic monitoring of boreal aquatic habitats using ‘subtle signs’ and oral histories

“…In Finland similar species and habitats suffer from river regulation measures, including impoundment, hydro peaking, dredging and embanking (Aronsuu et al 2015). Shasteen (2007), Grabarkiewicz and Davis (2008), Civas and Kesminas (2011), Li et al (2014) and Jazdzewski et al (2016) confirm brook lampreys to be intolerant of pollution and habitat disturbance, with their presence acting as an indicator (Degerman et al 2016) of good water and substrate quality. Li et al (2014) refer additionally to the cultural values various lamprey species have.…”

“…Schroll (1959) and Freyhof (2011) provide an overview of brook lamprey (Lampetra planeri) and in Finnish waters the situation has been investigated by Aronsuu and Virkkala (2014) and Yrjölä et al (2015). It is listed under Annex II of the European Habitats Directive (Jazdzewski et al 2016).…”

Sampling Methods and Survey Designs for Larval Lampreys

“…The scope of inference is determined by the spatial extent, spatial distribution, survey design, the size of sampling units (e.g., 1‐m 2 , 100‐m reach or some other size unit), and the number of sites within and across habitats (Table 4; Harvey and Cowx 2003; USFWS 2014). The spatial extent may include microhabitats (Torgerson and Close 2004) nested within transects (Pajos and Weise 1994; Fodale et al 2003; Jażdżewski et al 2016), channel units within stream segments (Starcevich and Clements 2013), entire stream reaches or segments (Claire et al 2007; Schultz et al 2014), or watersheds (Ferreira et al 2013).…”