Lingulid brachiopod collected from central Sagami Bay, Japan, by dredge sampling in 2009

抄録

We investigated the benthic fauna in central Sagami Bay, Japan, using dredge sampling from 2006 to 2019. When we rechecked all the samples, two lingulid brachiopod individuals were discovered in those collected in 2009. The shell shape and pedicle features of these lingulids were similar to those of Lingula reevei. However, some distinct morphological characteristics, including the separation of the anterior and median internal oblique muscles from the perimial line, were also observed in these individuals. In genetic analyses using the DNA sequences of nuclear 28S rRNA and H3, as well as mitochondrial 16S rRNA and COI, one lingulid individual, from which we successfully extracted total DNA, differed by only one base pair in the COI from a known member of the L. reevei complex from the waters adjacent to Japan. The genetic distance between this individual and L. reevei collected from the type locality in Hawaii was substantial. Therefore, L. aff. reevei and the known member of the L. reevei complex from the waters adjacent to Japan are the same species but should not be identified as L. reevei.