Yr wylan gefnddu fwyaf yw’r wylan fwyaf yn y byd! Oherwydd ei maint, ychydig o ysglyfaethwyr sy’n ceisio ymosod arni, ond gall fod yn fyrbryd blasus o dro i dro i eryrod cynffon gwyn, siarcod a…

This brightly coloured and easily recognizable fish is one of three gurnard species found in UK seas. Collectively, gurnards are known as sea robins.

This slender and elegant shark species is often found close to shore all around our coasts and can grow up to 6 feet long.

This purply-brown seaweed is a common feature on our rocky shores and on our dinner plates.

These mat like growths found on kelp and seaweed are actually colonies of tiny individuals animals.

The Common walnut tree produces a large, brown nut that is familiar to so many of us. It is an introduced species in the UK, and can be seen in towns, gardens and parks.

Fat hen is a persistent 'weed' of fields and gardens, verges and hedgerows. But, like many of our weed species, it is a good food source for birds and insects.

Freshwater pearl mussels spend their adult lives anchored to the river bed, filtering water through their gills and improving the quality of the water for other species.

The Migrant hawker is not a particularly aggressive species, and may be seen feeding in large groups. It flies late into autumn and can be seen in gardens, grasslands and woodlands.

Pineappleweed is an introduced species that has become a widespread 'weed' of disturbed ground, such as pavements and roadsides and gardens. It has feathery leaves and yellow flower…