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
Astyanax microschemos its middle caudal fin; a faint dark pigmentation is also present in the middle of caudal fin rays. The previously described stripe extends dorsally and ventrally close to the caudal fin base, forming a small caudal spot. The fish also exhibits a solitary black, narrow, and vertically elongate humeral spot, located over the second to fourth lateral line scales and which extends over 2-3 horizontal series of scales. Fins have scattered dark chromatophores. "A. microschemos" is only known from the river source of the Itapemirim River, in Espírito Santo, eastern Brazil. At the type locality where the animal was first