As for all the species of the genus Chrysallida, C. fischeri has an heterostrophic embryonic protoconch with a 120° inclined axis ("type B" according to van Aartsen, 1987); so that, being intorted, the apex appears hidden in the following whorl. Axial ribs are well marked, stronger than the fine and conspicuous spirals, covering the whole surface of each whorl. The suture is well marked and the columella is inclined to left, with a prominent tooth.
white or cream.
common size :
the holotype measures 2.6 mm in length.
A clear columellar tooth, well distinguishable at an accurate observation, characterises this pyramidellid as belonging to the genus Chrysallida, instead of Turbonilla, which lacks columellar structures. Among the Mediterranean Chrysallida, this species most closely resembles C. decussata (Montagu, 1803), from which it differs in being more cylindrical: last whorl/total height ratio is rather ½ in C. fisheri and 2/3 in C. decussata. It also resembles the exotics Chrysallida maiae, which is larger and has a stouter outline, and Turbonilla edgari (Melvil, 1869), which has a different insertion of the protoconch whorls.
BIOLOGY / ECOLOGY
Pyramidellidae are ectoparasites, mainly of sedentary polychates and molluscs.
records do not provide habitat information for the species in the Mediterranean. In Israel and Turkey the shells were found in 40-70 m and 0-12 m depth, respectively.