These colourful little fish are a delight for snorkellers or shallow water divers to photograph, rarely being scared off by their presence!

A breeding bird of fast-flowing, upland rivers, the grey wagtail can also be seen in lowland areas, farmyards and even towns in winter.

Perennial rye-grass is a tufted, vigorous grass of roadside verges, rough pastures and waste ground. It is commonly used in agriculture and for reseeding grasslands.

Tansy is an aromatic plant of rough grassland, riverbanks and verges that has button-like, yellow flower heads. It is the main foodplant of the rare Tansy Beetle, now found at only two places in…

A small colourful sea slug that can be found grazing on sea mats on the rocky shore and beyond the low water mark.

Their long narrow shells are a common sight on our shores, especially after storms, but the animals themselves live buried in the sand.

The thresher shark is a migratory species and passes through UK waters in the summer months. If you’re lucky, you might see this magnificent shark jump high out of the water in to the air.

The common octopus is a highly intelligent, active predator. It even has a secret weapon - special glands produce a venom that it uses to incapacitate its prey!

Mae'r siarc main yma’n cael ei enw o'r pigau o flaen ei asgell ddorsal. Gall ddefnyddio'r pigau yma i amddiffyn ei hun drwy gyrlio mewn bwa a tharo ysglyfaethwr.