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.

Orca, sometimes known as ‘killer whales’, are unmistakable with their black and white markings. Although we do have a small group of orca who live in British waters, you would be lucky to see them…

Parsley fern lives up to its name - the pale green fronds form in clusters among rocks and look just like parsley. Look out for it in upland areas, particularly in Wales and Cumbria.

The pyramidal orchid lives up to its name - look for a bright pinky-purple, densely packed pyramid of flowers atop a green stem. It likes chalk grassland, sand dunes, roadside verges and quarries…

The Yellow slug lives up to its name - its yellow body is mottled with grey patches. Often found in gardens and damp places in houses, it can be considered a pest, but is an important nutrient…

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…

You are most likely to spot the cat flea if you have pets. It will feed on cats, dogs and people, although it can't live on us. It is a pest and needs to be controlled in the house for the…

The small, brown Dartford warbler is most easily spotted when warbling its scratchy song from the top of a gorse stem. It lives on lowland heathland in the south of England, where it nests on the…

Despite its name, the marsh tit actually lives in woodland and parks in England and Wales. It is very similar to the willow tit, but has a glossier black cap and a 'pitchoo' call that…