Tarsus (eyelids) is a groove in the inner surface of each eyelid. Along the inner margin of the tarsus are modified sebaceous glands known as tarsal glands (or meibomian glands), aligned vertically within the tarsi: 30 to 40 glands in the upper lid, and 20 to 30 in the lower lid, which secrete a lipid-rich product which helps keep the lacrimal secretions or tears from evaporating too quickly, thus keeping the eye moist. Tarsus (eyelids) The tarsi (tarsal plates) are two comparatively thick, elongated plates of dense connective tissue, about in length; one is found in each eyelid, and contributes to its
Oily fish Oily fish Oily fish have oil in their tissues and in the belly cavity around the gut. Their fillets contain up to 30% oil, although this figure varies both within and between species. Examples include small forage fish, such as sardines, herring and anchovies, and other larger pelagic fish, such as salmon, trout, tuna, swordfish and mackerel. Oily fish can be contrasted with white fish, which contain oil only in the liver, and much less overall than oily fish. Examples of white fish are cod, haddock and flatfish. White fish are usually demersal fish which live on or near the