To test the effects of diatom production on larval fish growth and condition, laboratory experiments were performed with larval North Sea cod reared on different algal food chains. These food chains were based on cultures of (a) the diatoms Skeletonema costatum and Thalassiosira weissflogii; (b) the dinoflagellate Heterocapsa triquetra; (c) the flagellate Rhodomonas baltica; (d) a diet composed of both Skeletonema and Heterocapsa food chains (1:1), and (e) a starvation group. These algae were fed to cultures of adult Acartia tonsa. Copepod eggs were collected, hatched, and the N1 nauplii (200 l 1 ) were fed to post-yolk-sac larval cod. Results indicate that larval growth rates are significantly influenced by the content of essential fatty acids of the algal food source: growth rates were positively correlated with the content of DHA (C22:6 3) and negatively with EPA (C20:5 3). The ratio of 3/ 6 fatty acids in the algal source had no significant effect. The highest and lowest growth rates were observed in food chains based on H. triquetra and T. weissflogii, respectively (means for days 14-16 of 4.0 and 4.7). The mixed diatom/dinoflagellate diet resulted in intermediate growth rates and condition. Regressions of growth rates against EPA and DHA content indicated no inhibitory effect of diatom production on growth in larval cod.

Little is known about the community of dragonflies and damselflies in Tampa Bay, Florida, USA. To address this gap, we conducted 2 longitudinal surveys of adult odonates in a natural floodplain of the Hillsborough River in 2013 and 2017. Along with abundance and species diversity, we also measured intraspecific variation in body size, sexual dimorphism, wing-cell asymmetry, and water mite ectoparasitism. Our first weekly survey from Oct 2013 to Oct 2014 sampled 327 adults (230 female, 97 male) from 8 dragonfly species, with the eastern pondhawk (Erythemis simplicicollis Say; Odonata: Libellulidae) representing 79% of captures, followed by the second most abundant (14%), the Florida non-native and neotropical hyacinth glider (Miathyria marcella Selys; Odonata: Libellulidae). Our second weekly survey from Sept to Dec 2017, which focused on both damselflies and dragonflies and captured 205 adults from 8 species, with the fragile forktail (Ischnura posita Hagen; Odonata: Coenagrionidae) being the most abundant with 70% of captures. Female-biased sexual size dimorphism was found in both E. simplicicollis and I. posita; however, both sexes were equally variable in size and symmetric in a meristic trait. Female and male M. marcella were equally variable, monomorphic, and symmetric. Combing symmetry data from each sex, only I. posita damselflies were asymmetric overall. Finally, we did not observe any parasitism by larval water mites in either survey. We aim to continue surveys to track seasonal and climate-driven changes in dragonfly diversity and phenology in this region.