Development and application of a second-generation multilingual tool for invasion risk screening of non-native terrestrial plants.

Under the increasing threat to native ecosystems posed by non-native species invasions, there is an urgent need for decision support tools that can more effectively identify non-native species likely to become invasive. As part of the screening (first step) component in non-native species risk analysis, decision support tools have been developed for aquatic and terrestrial organisms. Amongst these tools is the Weed Risk Assessment (WRA) for screening non-native plants. The WRA has provided the foundations for developing the first-generation WRA-type Invasiveness Screening Kit (ISK) tools applicable to a range of aquatic species, and more recently for the second-generation ISK tools applicable to all aquatic organisms (including plants) and terrestrial animals. Given the most extensive usage of the latter toolkits, this study describes the development and application of the Terrestrial Plant Species Invasiveness Screening Kit (TPS-ISK). As a second-generation ISK tool, the TPS-ISK is a multilingual turnkey application that provides several advantages relative to the WRA: (i) compliance with the minimum standards against which a protocol should be evaluated for invasion process and management approaches; (ii) enhanced questionnaire comprehensiveness including a climate change component; (iii) provision of a level of confidence; (iv) error-free computation of risk scores; (v) multilingual support; (vi) possibility for across-study comparisons of screening outcomes; (vii) a powerful graphical user interface; (viii) seamless software deployment and accessibility with improved data exchange. The TPS-ISK successfully risk-ranked five representative sample species for the main taxonomic groups supported by the tool and ten angiosperms previously screened with the WRA for Turkey. The almost 20-year continuous development and evolution of the ISK tools, as opposed to the WRA, closely meet the increasing demand by scientists and decision-makers for a reliable, comprehensive, updatable and easily deployable decision support tool. For terrestrial plant screening, these requirements are therefore met by the newly developed TPS-ISK.

Reproductive traits of the spirlin Alburnoides bipunctatus in the Vistula River basin.

The aim of the current study was to examine whether environmental conditions may explain interpopulation variation in fecundity and egg size of the spirlin from two rivers of the Vistula River basin. The obtained results indicated that the reproductive performance, including the gonadosomatic index, was similar in both rivers and fecundity increased with total length of females. The observed differences in water temperatures and flow speed between the rivers were too small to cause discernible differences in the reproductive performance of fish.

Feeding activity of spined loach Cobitis sp. in Lake Lucien, Poland.

The feeding activity of spined loach Cobitis sp. was studied in post-glacial ribbon Lake Lucien, Central Poland, during three 24 hrs periods in May, August and September. Samples were taken every 4 hrs and 8 to 18 (mode 10) specimens were caught on each sampling occasion. A total of 233 fish (37.3-107.6 mm TL) gut contents were examined. Six main food components (Cladocera, Chironomidae (larvae and pupae), Copepoda, Ostracoda, other macroinvertebrates and detritus) were used by the fish. Precise identification of gut contents showed that spined loach consumed large numbers of food items (from 31 to 39). Nevertheless standardised form of Levin's and Shannon-Wiener's indices revealed a rather narrow food niche, which was a result of unequal proportions of food items in gut contents and domination of few prey categories. Spined loach fed mostly from post-dusk to dawn and achieved maximum gut fullness in the morning (4.00-8.00). This nocturnal feeding pattern was consistent throughout all sampling occasions, but there was some discrepancy concerning 12.00 hours in spring and summer. Due to this, early morning activity can not be excluded. Prey selection indices indicated that spined loach preferentially consumed some small size chironomids: Tanytarsus, Cladotanytarsus, Dicrotendipes and avoided larger ones (Glyptotendipes, Stictochironomus).

Microhabitat preferences of spined loach, Cobitis sp. in the Grabia River--multivariation approach.

The pattern of microhabitat preferences of spined loach was examined in a natural, unpolluted lowland river. This fish co-occurred with 9 other species but non-random association was noted only with Ukrainian Lamprey, the most abundant species in the studied fish community. Spined loach was distributed only in areas adjacent to river banks. Microhabitat variables configuration available for the examined fish was represented by three axes obtained by principal component analysis. The presence/absence distribution pattern of spined loach was negatively dependent on the abundance of gravel and pebbles (component 1) and positively related to low velocity (component 3). The abundance of coarse sand (component 2) had no effect on the spined loach distribution pattern and fish randomly used this type of microhabitat. Although that substratum particle size plays an important role in spined loach distribution, in the natural environment this fish realised its microhabitat preferences by the avoidance of unfavourable configuration ofmicrohabitat variables such as high velocity and coarse-grained substrata (gravel and pebbles).

Growth and reproductive biology of loaches Cobitis sp. in Lake Lucien, Poland.

Five age-classes and their corresponding average body lengths of loaches from Lake Lucien were determined by the Bhattacharya method. The maximum observed length was 112 mm for females and 91 mm for males. The von Bertalanffy equation defining growth pattern was L(T) = 116 (1-exp (-0.401(t+0.02. Body length distribution of females and males differed significantly (chi2 = 91.295; df=9; P<0.00). Sex ratio showed the dominance of females in the studied population (M:F = 1:1.75; chi2 =18.00; P<0.01). Females were sexually mature at 56 mm TL and males at 52 mm TL. Female gonad weight increased with body size. The frequency distribution of egg diameters revealed 3 groups of oocytes. The average absolute fecundity was 2180 eggs and ranged from 418 to 6800 per gonad. The number of the largest oocytes (>0.6 mm in diameter) ranged from 208 to 975 (average 501) and was used to estimate fecundity at the moment of spawning. Both fecundity measures are related to body length of females their regression lines were parallel and did not differ in the coefficient of slope. The gonadosomatic index value, as an approximate measure of reproductive effort, was rather small (average IGS = 10.44 ranged from 5.12 to 17.88).