Abstract
Four new species of the genus Orobdella Oka, 1895 from the mountainous regions of Shikoku and Awajishima island, Japan are described. These new species consist of one quadrannulate, two sexannulate and one octannulate species. The quadrannulate Orobdella brachyepididymis sp. n. is a small species with a body length reaching only ca. 5 cm. The sexannulate Orobdella okanoi sp. n. was collected from Shikoku, and the other sexannulate species, Orobdella yamaneae sp. n., inhabits Awajishima island. The octannulate Orobdella nakahamai sp. n. is a large species with a body length greater than 20 cm and is only the second large octannulate species known within this genus. Phylogenetic analyses using nuclear 18S rRNA and histone H3, as well as mitochondrial cytochrome c oxidase subunit I, tRNACys, tRNAMet, 12S rRNA, tRNAVal, 16S rRNA, tRNALeu and NADH dehydrogenase subunit 1 markers, indicated that O. brachyepididymis is a sister species of the quadrannulate O. naraharaetmagarum Nakano, 2016, while the other three new species formed a clade closely related to O. masaakikuroiwai Nakano, 2014 and O. whitmani Oka, 1895. The ranges of the distant phylogenetic lineage groups of Orobdella overlap in Shikoku and adjacent islets.
Highlights
The genus Orobdella Oka, 1895 is a terrestrial macrophagous leech taxon that inhabits the Japanese Archipelago, Korean Peninsula and Taiwan (Nakano and Lai 2012, Nakano and Seo 2014, Sawyer 1986)
The other species O. octonaria Oka, 1895 is an octannulate taxon. These 13 species can be split into another three types based on the body lengths of mature leeches (Nakano 2016): three quadrannulate species belong to the small-type; the other five quadrannulate and all sexannulate species are designated the middle-type; and the octannulate species is assigned to the large-type
No clear genetic distance gap exists between O. brachyepididymis and O. naraharaetmagarum, the new species is clearly distinguished from O. naraharaetmagarum by the following combination of morphological characters (Table 2): morphology of the gastroporal duct, number of annuli between gonopores, lengths of epididymides and morphology of the male atrial cornua
Summary
The genus Orobdella Oka, 1895 is a terrestrial macrophagous leech taxon that inhabits the Japanese Archipelago, Korean Peninsula and Taiwan (Nakano and Lai 2012, Nakano and Seo 2014, Sawyer 1986). The latest taxonomic study on this genus showed that Orobdella contains 13 species (Nakano 2016) split into three groups based on their mid-body somite annulation: eight species in the quadrannulate (four annuli per one somite) group and four species in the sexannulate (six annuli) group. The other species O. octonaria Oka, 1895 is an octannulate (eight annuli) taxon These 13 species can be split into another three types based on the body lengths of mature leeches (Nakano 2016): three quadrannulate species belong to the small-type (of which the body lengths of mature leeches are shorter than 5 cm); the other five quadrannulate and all sexannulate species are designated the middle-type Molecular phylogenetic analyses of the Orobdella species clearly showed that these morphological groups or forms do not reflect phylogenetic relationships (e.g. Nakano 2016): the sexannulate mid-body somite annulation and the small-type body length have evolved in parallel in the genus
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
