The smalltooth sawfish is the first documented examples of viable parthenogens living in a normally sexually reproducing wild vertebrate.

The researchers analysed telltale markers called microsatellites in 190 sawfish that reveal how related their parents are. In seven fish, the markers suggested their parents were identical to them. The analysis revealed that the seven fish came from three different mothers.

In many cases, stock assessment is based on fishery-dependent data generated from fish markets or creel surveys. The assumption is: that the lower the catches in a certain unit of time, the smaller the stock of fish should be.

However German researchers have just shown that some fish species show enhanced gear-avoidance behaviour in regions with high angling intensity compared to fish exposed to low levels of exploitation near marine protected areas. The consequence is the impression that there are fewer fish in the sea, which does not necessarily agree with underwater reality.

Although seagrass meadows occupy less than 0.2 percent of the world's oceans, they are responsible for more than 10 percent of all carbon buried annually in the sea, according to a research paper published this week in the journal Nature Geoscience.

The paper, "Seagrass Ecosystems as a Globally Significant Carbon Stock," is the first global analysis of carbon stored in seagrasses.