Caudal mucous pit Caudal mucous pit The caudal mucous pit, or caudal mucous horn, is an anatomical structure on the tail end of the foot of various land snails and slugs, terrestrial pulmonate gastropod mollusks. The function of this pit is the resorption of mucus when the gastropod is moving (see also Muratov 1999). An incorrect and yet often-used term for this structure is the "caudal gland". This area also used to be referred to by the term "caudal pore". Families of snails and slug where a caudal mucous pit exists in every species included: Families/subfamilies where is caudal mucous pit exists only
Sardinella maderensis while also having a variably protruding belly. These fish have a median number of gill rakers and their upper pectoral fin rays are white on the outer side with a black membrane in between. They are very hard to distinguish from "Sardinella aurita" except that these fish have only 7 rays on their pelvic fins and no black spot on the hind part of their gill cover. They also have a gray caudal fin (see Fish anatomy) with black tips. "S. madarensis" catches have decreased from 1.8 tonnes per trip in 2003 down to 1.5 tonnes in the following two