SYSTEMATICS

・PREVIOUS RESEARCHES (THEORETICAL)
Integrated framework of biological taxonomy (IFBT)
     Supposing that we systematists can avoid taxomomic rank problems while retaining all the information that taxonomic ranks provide in the Linnean system, I propose an integrated framework of biological taxonomy (IFBT), into which advantages of the phylogenetic taxonomy and (some important elements of) Linnean nomenclature, together with the temporal banding methods (Hennig, 1966; Avise and Johns, 1999), are synthesized in a harmonious manner. In order to reconcile the theory of IFBT with the evolutionary world view, the IFBT aims at creating a rank-free phylogenetic system, whose components are only the names of evolutionary clades (as taxa). Here, the categories of evolutionary clades that I recognize are ‘basic clade’, ‘holoclade’ and ‘synclade’. The whole area (all taxon names) of a phylogenetic system of taxon names created under the IFBT is called ‘general domain’, while its part (basic clade names) is called ‘particular domain’. By introducing the method of using ‘names with standard endings’ into the present clade nomenclature, in other words, by adopting the temporal bands of geological periods as the only criteria for assigning the standard endings to basal clade names in naming clades, we name the clades, so that we can create the particular domain of phylogenetic system (of taxon names) that takes basically the same style as the Linnean system (of taxon names), in that taxon names with the standard endings are arranged in a hierarchical manner (Naomi, 2014; See ALL PUBLICATIONS: I).

・PREVIOUS RESEARCHES (PRACTICAL)
(1) Phylogeny and higher classification of Staphylinoidea
     The phylogeny and higher classification of Staphylinidae and allied groups are studied, based on the examination and dissection of about 120 genera and species of Staphylinoidea in addition to important information found in the previous papers on the Staphylinoidea (Naomi, 1985; See PUBLICATIONS: II).
(2) Phylogeny and biogeography of Anisolinus (Staphylininae)
     Based on the information of distributions and the phylogenetic trees on the 5 Japanese species, the phylogeny and biogeography of the 5 species of genus Anisolinus sharp of Japan is hypothesized and discussed (Naomi, 1991; See ALL PUBLICATIONS: II).
(3) Monograph of the subfamily Steninae (Staphylinidae) of Japan
     This is the monographic study of Japanese Steninae, in which the adult morphological characters and their various conditions are adopted for the sake of the identification and taxonomy of species. The Japanese Steninae consists of 2 genera (Dianous and Stenus), 39 species groups (3 species groups in Dianous and 36 species groups in Stenus) and 346 species (6 species in Dianous and 340 species in Stenus) (Naomi et al., 2017, 2019 and 2022; See ALL PUBLICATIONS: III).
(4) Taxonomic studies of Staphylinidae
     The Japanese species of subfamily Megalopsidiinae, Piestinae and Osoriinae are revised. New species of Oxytelinae (Thinobius), Trichophyinae (Trichophya), Tachyporinae (Sepedophilus), Aleocharinae (Oligota, Hypocyptus, Trichopsenius, Kistnerium, Gymunusa, etc.), Pselaphinae (Mayetia), Staphylininae (Anisolinus, Phytolinus, Protocypus, etc.), Paederinae (Ochthephilum), etc. are described from Japan, except for some species from Taiwan and Nepal (Aleocharinae, Odontoxenus and Doryloxenus species), from Papua New Guinea (Leptotyphlinae, Newtonius species), and from Taiwan (Staphylininae, Phytolinus species), etc. (These taxonomic studies are written by me or by me and my colleagues; See ALL PUBLICATIONS: IV).

・PRESENT INTERESTS
     I am interested in the theory and practices of naming clades under the IFBT.

SPECIES PROBLEMS

・PREVIOUS RESEARCHES (THEORETICAL)
Integrated framework of species concept (IFSC)
     IFSC treats the idea of species as population-level evolutionary lineages (i.e., evolutionary species concept, sensu Wiley 1978) as the concept for species category while it adopts the contingent biological properties of species (e.g. internal reproductive isolation, diagnosability, monophyly) as operational criteria in delimiting species (Naomi, 2011; See ALL PUBLICATIONS: I).

・PRESENT INTERESTS
     I am interested in the further development and dissemination of evolutionary species concept.

MORPHOLOGY

・PREVIOUS RESEARCHES (PRACTICAL)
(1) Morphology of the thorax and abdomen of Coleoptera
     Thorax: The prevailing idea on the morphology of prothorax in Coleoptera is reexamined, and reinterpreted under the Matsuda’s (1970) framework of insect thorax. One important result is that the ventral plate (or so-called “sternum” in descriptive studies) in all Coleoptera is sternal in origin, but not a composite plate into which the sternal and pleural elements are fused. A groundplan of the prothoracic structure of the stem Coleoptera is described and discussed, with a hypothesis that the pleuron consists of at least the four pleurites (preepisternum, anepisternum, katepisternum and epimeron) (Naomi, 2014; See ALL PUBLICATIONS: II).
     Abdomen: The pregenital abdominal segments of Coleoptera basically consist of the tergum (mediotergite and laterotergite), membranes, and pleurosternum (lateroventrites + solidiventrites [tritiventrites + medioventrite]). The important result (suggested previously in 1935 by Snodgrass) is that the lateroventrites (= parasternites sensu Kasap and Crowson, 1975; paratergites auct.; etc.) are secondary lateral subdivisions of the pleurosternum. Three basic forms of the structure and composition of pregenital abdominal segments in Coleoptera are described and discussed (Naomi, 2014; See ALL PUBLICATIONS: II).
(2) Comparative morphology of Staphylinidae (Coleoptera)
     The comparative morphology of the head, thorax and abdomen of Staphylinidae and allied groups is studied, basically under the framework of Sndograss’s (1935) theory (head and abdomen) and of Matsuda’s (1970) theory (thorax) (Naomi, 1987-1990; See ALL PUBLICATIONS: II).
(3) Morphology of the male aedeagus and its endophallus in Staphylinidae (Coleoptera)
     Staphylinidae: Concerning the Staphylinidae, structures and functions of the endophallic copulatory tubes of male aedeagus are studied, which have been previously called “copulatory piece”, “endophallus”, “flagellum”, etc. in descriptive studies. Structures of the copulatory tubes in Staphylinidae are described, paying special attention to those of Steninae. Function of the copulatory tube is hypothesized as follows: it is simply a “spermatophore (or sperm) depositor” in some cases (e.g., Steninae, some Stenus), whereas it is twofold: a “spermatophore (or sperm) depositor” and an “extension-tube (or sperm) guiding rod in some other cases (e.g., Aleocharinae, some Aleochara) (Naomi, 2018; See ALL PUBLICATIONS: II).
     Stenus (Steninae):  Structures and functions of the aedeagal median lobe and endophallic components of the genus Stenus are studied. The dorsal membrane, dorsolateral (longitudinal) bands, expulsion hooks, copulatory tube, diverticula and ventromedian (longitudinal) bands are here recognized as major endophallic components of the aedeagus in Stenus. The copulating mechanism of Stenus is described and discussed, paying special attentions to the genital connections during copulation and the three-staged process of copulatory connection (Naomi, 2018; See ALL PUBLICATIONS: II). A probable endophallic copulatory tube gland is discovered only from the male of  Stenus rufescens (Naomi et al., 2022; See ALL PUBLICATION: III).

・PRESENT INTERESTS
     I am interested in the theory of homology and related concepts and matters in morphology.