The underlying mechanisms responsible for ecological plasticity and consequent invasive character of non‐native freshwater fish species, variations in growth and life history traits in gibel carp Carassius gibelio (Bloch) were compared in natural and artificial water bodies of Turkey. Females significantly outnumbered males in all natural and most artificial waters. Discriminate function analysis differentiated gibel populations into three separate groups (natural lakes, artificial water bodies and running waters), with significant differences among separated groups in growth index, standard length and age at maturity, relative fecundity and gonado‐somatic index, but not in egg diameter and both generalised and relative condition. Growth features (e.g. growth index and relative condition) and reproductive features (e.g. relative and absolute fecundity) positively correlated with water body area. No correlations were found for any growth or life history trait with depth, latitude and altitude. With the exception of smaller size at maturity, all traits were higher in populations from artificial water bodies than those inhabiting running waters, suggesting gibel carp is required to exert more reproductive effort to invade natural ecosystems than artificial waters.

The age, growth and reproduction are described for 411 individuals of abu mullet from the Orontes River in Turkey between May 2011 and April 2012. The overall male to female ratio was 1:1.29. Fork length of all individuals ranged from 2.2 to 18.5 cm and total weight from 1.85 to 66.40 g. Isometric growth was observed for males (b=2.938) and all individuals (b=2.907); positive allometric growth was observed for females (b=3.246). The von Bertalanffy growth parameters based on data from otoliths were L ∞ = 19.48 cm, k=0.258 year -1 and t 0 =-1.738 years for males, L ∞ = 20.31 cm, k=0.313 year -1 and t 0 =-1.432 years for females. The growth performance index ( ) was found to be 1.99 for males, 2.11 for females and 2.18 for all individuals. The mean condition factor (K) was calculated as 0.792±0.027 for males and 0.835±0.030 for females. Length at maturity was 11.49 cm for males and 11.82 cm for females. The fecundity was 14413±1569 with an egg diameter of 0.44±0.07 mm. Spawning period was between April and August. Abu mullet has acclimated well in the Orontes River and is capable of successful reproduction. Its calculated age and size at maturity was smaller and younger than for other populations.

Gracilaria vermiculophylla, a red macroalga from the West Pacific, was discovered in western Germany (the Wadden Sea) in 2002 and has since also been observed in Sweden (from about 70 km south to about 80 km north of Göteborg), Denmark (Wadden Sea, Horsens Fjord, Limfjorden, Vejle Fjord, Holckenhavn Fjord, Øster Hurup Harbor) and eastern Germany (Kiel Bay). Today, less than 5 years following its first observation in the Wadden Sea the invader is common in many invaded regions, often being amongst the most abundant macroalgal species. G. vermiculophylla is successful in shallow protected soft-bottom estuaries and bays, typically in association with ubiquitous native invertebrates (lugworms, tube-building worms, mussels, cockles, snails). The invertebrates provide substratum for holdfast attachment and thalli incorporation, most likely increasing the stability of local G. vermiculophylla populations. We hypothesize that this substratum provision is highly important for its general invasion success. We also confirm that G. vermiculophylla can maintain growth at all salinities experienced along Danish coastlines (8.5-34 psu). In addition, laboratory experiments indicate that the ubiquitous grazer Littorina littorea has the potential to control G. vermiculophylla growth under specific environmental conditions, but also that L. littorea may facilitate small-scale dispersal within invaded locations, because grazing increases thalli fragmentation rates. Given its widespread distribution, rapid range expansion, and known ecological traits, G. vermiculophylla is clearly a permanent resident of northern European waters.

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Summary Length–weight and length–length relationships are presented for four freshwater fish species [Liza abu (Heckel, 1843), Aphanius mento (Heckel, 1843), Oxynoemacheilus hamwii (Krupp & Schneider, 1991) and Chondrostoma kinzelbachi Krupp, 1985] captured in Gölbaşı Lake, Hatay, Anatolia. No information regarding length–weight relationships was reported previously in FishBase for C. kinzelbachi, A. mento and O. hamwii. Specimens were obtained from January to May 2012 using electrofishing and cast nets. This study presents the first study on LWR data for C. kinzelbachi, A. mento and O. hamwii.