The word 'their' is not a noun. The word 'their' is a pronoun, a possessive adjective. The pronoun their takes the place of a plural noun (or two or more nouns) that describes â¦ something as belonging to that noun(s).
This species can reach a length of 11 centimetres (4.3 in) TL. This species is sometimes kept in public aquariums. The sand goby is of a sandy colour, with darker markings on the sides and a creamy-white underside. In the breeding season the male fish has blue spot at the rear of the first dorsal fin, ringed with white.The fish has a slender body, and the head is about a quarter of the total length.his species can reach a length of 11 centimetres (4.3 in) TL. This species is sometimes kept in public aquariums. The sand goby is of a sandy colour, with darker markings on the sides and a creamy-white underside. In the breeding season the male fish has blue spot at the rear of the first dorsal fin, ringed with white.
The Sand dollars, are species of flattened, burrowing sea urchins belonging to the order Clypeasteroida. Echinarachnius parma, the Common Sand Dollar, is widespread in the Northern Hemisphere, from the intertidal zone to considerable depths.hey are softer and much shorter than those of the sea urchin. Like all echinoderms, sand dollars have tube feet. They are not used to move around, but simply to breathe. The sand dollar's tube feet actually stick out of the top of the sand dollar.