For the last few decades, trophic ecology has usually been investigated by using stable isotopes. However, the isotopic signatures of potential food sources in hydrothermal vent ecosystems are often unknown and so their relative contribution to the consumers’ diet, as well as resource partitioning, are then difficult to estimate. Here, we used a recent B ayesian mixing model (stable isotope analysis in R , SIAR ) based on δ 13...

Summary The shrimp Rimicaris exoculata from hydrothermal vents on the Mid‐Atlantic Ridge (MAR) harbours bacterial epibionts on specialized appendages and the inner surfaces of its gill chamber. Using comparative 16S rRNA sequence analysis and fluorescence in situ hybridization (FISH), we examined the R. exoculata epibiosis from four vents sites along the known distribution range of the shrimp on the MAR. Our results show that...

Male three‐spined stickleback Gasterosteus aculeatus have a fixed amount of sperm during the breeding season because spermatogenesis is inhibited at this time. A method was developed to estimate ejaculate size in situ by removing the sperm from the male's nest. The reliability of the method was tested using known numbers of sperm. In their first mating, males ejaculated 11·64 × 10 6 sperm (median), representing c. 5% of the ma...