Decreased Diversity and Abundance of Marine Invertebrates at CO Seeps in Warm-Temperate Japan.

Japan has many coastal carbon dioxide seeps as it is one of the most volcanically active parts of the world. These shallow seeps do not have the spectacular aggregations of specialist fauna seen in deep-sea vent systems but they do have gradients in seawater carbonate chemistry that are useful as natural analogues of the effects of ocean acidification on marine biodiversity, ecosystem function and fisheries. Here, we compare macroinvertebrate diversity and abundance on rocky habitats at ambient (mean ≤ 410 µatm) and high (mean 971-1484 µatm) levels of seawater CO in the warm-temperate region of Japan, avoiding areas with toxic sulphur or warm-water conditions.

First come, first served: precopulatory mate-guarding behavior and male-male contests by a hymenopteran saproxylic parasitoid.

Precopulatory mate-guarding behavior is a common strategy that maximizes male reproductive success when female receptivity to copulation is low. This behavior has been demonstrated in vertebrates, aquatic crustaceans, terrestrial isopods, and some species of insects, but there is very little available information about hymenopteran insects. A few studies have clarified the factor that determines the outcome of a contest between a guarding male and an invader male.