Boring bryozoans: an investigation into the endolithic bryozoan family Penetrantiidae

Abstract An endolithic lifestyle in mineralized substrates has evolved multiple times various phyla including Bryozoa. The family Penetrantiidae includes one genus with ten extant and two fossil species. They predominantly colonize the shells of molluscs establish colonies by chemical dissolution calcium carbonate. Based on several morphological characters, they were described to be either cheilostome or ctenostome bryozoans. For more than 40 years, neither characters species identity systematics nor problem their phylogeny was approached. Consequently, aim this study is reevaluate identities systematic position Penetrantia analyzing at least six different from eight regions aid modern methods such as confocal laser scanning microscopy 3D-reconstruction techniques. This demonstrates that musculature associated operculum brood chamber shows significant differences counterparts seems have independently. Together presence other ctenostome-like features true polymorphic stolons uncalcified body wall, finding supports a affinity. Operculum morphology reveals many new species-specific which, together information about gonozooid morphology, tentacle number, zooid size ranges, will enhance identification. It also revealed probable Japan well potential cryptic France New Zealand. In addition, increases known distribution range its substrate diversity. Altogether, collated here provides basis for future work neglected taxon.