Some shells of Ophieulima minima are reported from the Tuscan archipelago. This is the first record of the genus Ophieulima from the Mediterranean Sea. Hypotheses about its host are considered.

The family Eulimidae comprises minute gastropods best known for its parasitic habit on Echinodermata. Despite this, reports of association between eulimids and echinoderms are rather scarce. In this study, two new hosts, Parathyone suspecta and Holothuria grisea, were observed for the eulimid Melanella eburnea. This is the first record for the latter species in Brazilian waters. In addition we observed the association between the eulimid M. hypsela and the holuthurian Isostichopus badionotus, which is a new record for Brazilian waters.

Hypermastus tokunagai is a eulimid gastropod infecting the sand dollar Scaphechinus mirabilis. The eulimid is easily detached from the host and thus regarded as a temporary parasite. In this study, the growth and reproductive cycle of H. tokunagai were investigated using specimens collected from S. mirabilis in the western Seto Inland Sea, Japan. Newly recruited individuals of H. tokunagai appeared in early autumn and grew rapidly, while growth was retarded from mid-autumn to winter months. A second rapid growth occurred the following summer. Based on the growth pattern, the life span of H. tokunagai was estimated to be more than 20 months. This longer life span compared to other eulimids could be due to the accessibility and population stability of its host S. mirabilis. Maturation of H. tokunagai occurred within a short period in the summer, and was synchronized with the second growth phase. Hypermastus tokunagai showed size dimorphism between sexes and an investigation on change in shell shape with growth revealed that this characteristic can be attributed to the female's acquisition of a larger shell within a short time during its maturation period.