Two large structure-forming sponges from opposite North American coasts: a taxonomic review of Arctic–Pacific Mycale (Mycale) loveni and the description of a new Arctic–Atlantic Mycale

Mycale ( Mycale) loveni (Fristedt, 1887) is a very large structure-forming sponge that has previously been reported in the North Pacific, North Atlantic, and Arctic oceans. Through morphological and molecular examination, North Atlantic and Eastern Canadian Arctic specimens are now described as a new species, Mycale ( Mycale) lorea sp. nov. The two species have similar external morphology; however, the spicules that make up their skeletons differ in size and shape, and the species are also separated phylogenetically by multiple genetic markers.