Diversity and distribution of adeonid bryozoans ( Cheilostomata : Adeonidae ) in Japanese waters

Adeonid bryozoans construct antler-like erect colonies and are common in bryozoan assemblages along the Japanese Pacific coast. The taxonomy of Japanese adeonid species, however, has not been studied since their original descriptions more than 100 years ago. in the present study, adeonid specimens from historical collections and material recently collected along the Japanese coast are examined. Eight adeonid species in two genera were detected, of which Adeonella jahanai sp. nov., Adeonellopsis parvirostrum sp. nov., and Adeonellopsis toyoshioae sp. nov. are described as new species based on the branch width, size and morphology of frontal or suboral avicularia, shape and size of areolar pores, and size of the spiramen. Adeonellopsis arculifera (Canu & Bassler, 1929) is a new record for Japan. Lectotypes for Adeonellopsis japonica (ortmann, 1890) and Adeonella sparassis (ortmann, 1890) were selected among ortmann’s syntypes. Most species of Adeonellopsis around Japan have a southern distribution from sagami Bay to okinawa, while A. japonica shows a more northern distribution from Kouchi to otsuchi. in contrast, Adeonellopsis arculifera was collected only from southwestern Japan. A key to Japanese adeonid species is provided.


Introduction
order Cheilostomata in Class Gymnolaemata is the most speciose group of bryozoans in modern marine environments (Bock & Gordon 2013).While most cheilostome colonies are encrusting, forming an essentially 2-dimensional layer on the substrate, there are also many types of erect morphology in which the colony rises above the substrate in 3-dimensional space.Large, erect bryozoan colonies have contributed to the formation of bryozoan reefs or thickets from the Paleozoic to the present (Cuffey 1974(Cuffey , 1977;;Lombardi et al. 2014;McKinney & Jackson 1989;scholz et al. 2005;Probert & Batham 1979;Carter et al. 1985;Batson & Probert 2000;Taylor & James 2013;Wood & Probert 2013).Adeonid bryozoans (e.g., Adeonella Busk, 1884, Adeona Lamouroux, 1812, Adeonellopsis MacGillivray, 1886) form large, erect colonies with many flat, narrow, dichotomous branches, or are cribrate in form, which can be viewed as derived from dichotomously branched colonies, and contribute to assemblages of erect bryozoans in Japan (Hirose et al. 2012).
The family Adeonidae consists of approximately 10 genera and 106 species (Bock & Gordon 2013).One of the largest genera in the family, Adeonellopsis, comprises about 50 species that are almost globally distributed but are absent from higher latitudes (or alternatively: boreal and arctic waters).Another large genus, Adeonella, also comprises about 50 species, distributed in the Indo-West Pacific, Mediterranean, and Atlantic.Adeonellopsis has been reported from eocene deposits and is common throughout the later Cenozoic to recent.Adeonella has also been reported from eocene deposits in europe, but is more common in the present-day fauna.Hayward & Cook (1979, 1983) and Hayward (1981Hayward ( , 1988) ) described 27 new species of Adeonella from south Africa, where its diversity is remarkably high on the east coast (Hayward 1983(Hayward , 1988)).Compared to Adeonella, Adeonellopsis is more common and diverse in Australia and throughout the Indo-West Pacific.The Adeonidae have received a relatively great amount of attention over the past decades, a number of new species were introduced, and several known species revised (e.g., Cook 1982;Arístegui 1985;Hayward 1988;Amui 2005; rosso & Novosel 2010; Almeida et al. 2015).Moreover, owing to their complexity at zooidal and zoarial level, the ontogeny and astogeny of the Adeonidae is fairly well known (e.g., Cook 1973;Cheetham & Hayek 1983;Wass 1991;Lidgard & Buckley 1994;Lidgard 1996;Bock & Cook 2000, 2004;smith et al. 2001).Busk (1884) first described Adeonella as a genus in the family Adeonidae.Gregory (1893) later established the family Adeonellidae for Adeonella and related genera.some researchers followed Busk's original classification (Canu & Bassler 1920, 1923, 1929;Harmer 1957), andCook (1973) reported significant differences in frontal shield structure and development between Adeonella and the other genera in Adeonidae, and regarded Adeonella as clearly belonging in Adeonellidae.recently, however, Adeonellidae has been considered as a junior synonym of Adeonidae (Bock & Gordon 2013).
There are some previous records of adeonid bryozoans in Japan.ortmann (1890) reported three species from sagami Bay (Adeonella tuberculata Busk, 1884, and two new species, Adeonella japonica ortmann, 1890 and Adeonella sparassis ortmann, 1890).ortmann's type material, however, has not been restudied in detail.okada (1920) redescribed A. japonica from sagami Bay and described a new species, Adeonella hexangularis Okada, 1920, from the vicinity of the Miura Peninsula adjoining sagami Bay.subsequently, okada & Mawatari (1938) reported A. japonica from Wakayama Prefecture.Mawatari (1952) also reported A. japonica and A. hexangularis from Wakayama Prefecture, without any descriptions.The taxonomy of the Japanese adeonid bryozoans has previously not been reviewed and is still largely dependent on the limited descriptions in ortmann (1890), and their diversity and distribution around Japan remains poorly known.
For this study, I re-examined Ortmann's (1890) type specimens and examined other material collected in Japan over the past 130 years, as well as new material i collected personally.Here i review and describe or redescribe eight adeonid species in two genera from Japan, of which Adeonella jahanai sp.nov., Adeonellopsis parvirostrum sp.nov., and Adeonellopsis toyoshioae sp.nov.are described as new species, and summarize the distributions of all eight species around Japan.

Material examined
I examined specimens from Sagami Bay and surrounding areas (Appendix 1; Fig. 1A-B) collected by Ludwig Döderlein (1880-1881), emperor showa (1918-1971), and the National Museum of Nature and science Tokyo (2001-2005; 2006-2010); see National Museum of Nature and science (2007), Hirose (2010), andspencer Jones et al. (2011) for historical overviews.The material is housed at the Musée Zoologique strasbourg (MZs) and the National Museum of Nature and science Tokyo (NsMT), which is now located in Tsukuba (Appendix 1).At the Seto Marine Biological Laboratory (SMBL) of Kyoto University, I examined a specimen of Adeonella japonica collected from the vicinity of the Kii European Journal of Taxonomy 203: 1-41 (2016) Peninsula and reported by Okada & Mawatari (1938).I also examined adeonid specimens collected by the r/V Albatross from Japan and Hawaii and now housed in the National Museum of Natural History (UsNM), Washington, D.C. i collected additional specimens by dredge, grab, and beam trawl from several localities in Japan (Fig. 1A, C; Appendix 2), including Otsuchi (Iwate Prefecture), Maizuru (Kyoto Prefecture), the Sagami Sea, north of Hachijo-jima (south of the Sagami Sea), southwest of Kochi (Kochi Prefecture), the Ariake sea, Koshiki strait (west of Kyushu), and the Nansei islands from Tanegashima to okinawa.All of this material has been deposited in the NsMT in Tsukuba.

Preparation and observation of specimens
specimens were observed by light microscope and scanning electron microscope (seM) at Hokkaido University and at the Atmosphere and ocean research institute of the University of Tokyo (Aori).For seM observation, part of each specimen was soaked in a sodium hypochlorite solution to remove the soft tissue, rinsed in water, air dried, and mounted with double-sided adhesive tape or silver paste on an aluminum seM stub.At Hokkaido University, mounted specimens were coated with Au in a Hitachi e-1030 sputter-coater and observed at 15 kV accelerating voltage with a Hitachi s-3000N seM; at Aori, specimens were observed with a Hitachi Miniscope TM-1000 at 15 kV accelerating voltage without sputter-coating.All fragments removed from specimens in the various collections for seM observation were subsequently deposited in NMsT.
Measurements were taken from seM images with imageJ v. 1.37 software (image Processing and Analysis in Java, Wayne rasband, National institutes of Health, UsA; http://rsb.info.nih.gov/ij/).Measurements in the text are presented in micrometers, with the range followed by the mean and standard deviation (in HIROSE M., Japanese adeonid bryozoans parentheses).sample sizes for measurements were n = 2-115, and measurements were generally taken from more than one colony.Abbreviations used for characters measured are as follows: FAvL, FAvW = frontal avicularium length and width sAvL, sAvW = suboral avicularium length and width SOrL, SOrW = secondary orifice length and width spL, spW = spiramen length and width ZL, ZW = zooid length and width

Remarks
This family consists of approximately 10 genera and 106 species (Bock & Gordon 2013).Most genera form erect colonies with flat, dichotomous branches (e.g., Adeonella and Adeonellopsis) or are cribrate in form (e.g., Adeona), although some genera form encrusting colonies (e.g., Reptadeonella Busk, 1884).Adeonella and Adeonellopsis differ in the type of frontal shield: Adeonella has a lepralioid shield in which a spiramen leads into the space above the sinus, and a distinct primary orifice, while Adeonellopsis is thought to have an umbonuloid frontal shield and the spiramen leads into the space above the frontal membrane (Cook 1973;Lidgard 1996;Berning et al. 2014).Adeonella and Adeonellopsis are also different in the arrangement of the spiramen and frontal/suboral avicularia; Adeonella generally has a monoporous spiramen and frontal avicularia in various positions, whereas Adeonellopsis has a monoporous or multiporous spiramen, with a suboral avicularium situated distal to the spiramen, directed distally or distolaterally.

Remarks
This species was previously known as Adeonella platalea (Busk, 1854) in Japan.Lamarck (1816) first described Eschara lichenoides from the indian ocean, and Harmer (1957) transferred it to Adeonella.Harmer (1957) discussed the high variability in A. lichenoides and A. platalea; although he did not synonymize these species, he noted three groups of A. platalea based on variant forms of vicarious avicularia and mandible.Although Harmer's concept of the nature of intra-vs interspecific variation was different from that of more recent authors, Hayward (1988) restudied a syntype of Eschara lichenoides and found this specimen to be nearly identical to the paratype of A. platalea, and thus considered A. lichenoides to be a subjective senior synonym.Morphological variation within the extremely broad recorded distribution of this species from east Africa to eastern Australia, however, might indicate the presence of two or more unrecognized species.
Mawatari (1952) reported Adeona (Adeonellopsis) japonica from off Minabe and shirahama, Wakayama Prefecture, without any description but with a photograph of a single branch in which zooids have a swollen frontal shield with a single spiramen, quite resembling Adeonella.The photograph in Mawatari (1952) may be of a branch of A. cf.lichenoides (Brz.17) in the sMBL collection.

Distribution
Adeonella lichenoides has previously been reported from the Indo-West Pacific (Philippines, Malay Archipelago, Queensland coast, Torres strait, northern and western coasts of Australia and Victoria, and eastward to Zanzibar and east Africa) (Hayward, 1988). in Japan, Adeonella cf.lichenoides has been collected from sagami Bay, sagami sea, around the izu Peninsula, off the Kii Peninsula, the west coast of Kyushu (Koshiki strait), and ogasawara, at depths of 3-328 m.Although Adeonella cf.lichenoides was not collected from the eastern part of Sagami Bay by Döderlein or Doflein, it was very abundant in the western Sagami Sea (in ES collection) such as exposed shallow rocky habitat (3-45 m) at the southernmost part of the izu Peninsula (Hirose et al. 2012).European Journal of Taxonomy 203: 1-41 (2016) present along branch margins and at bifurcations.Gonozooids slightly larger than autozooids, with porous frontal shield; secondary orifice broad, with slightly convex proximal margin.

Remarks
Adeonella jahanai sp.nov.resembles A. lichenoides in having a granulated frontal shield, and in the location of the small, triangular frontal avicularium, but differs from the latter in having markedly narrower branches, numerous slit-like areolar pores on the frontal shield, elongate frontal avicularia, and the frontal avicularia directed proximally.Autozooids of Adeonella jahanai sp.nov.also differ from A. lichenoides in having another frontal avicularium, triangular, slightly projected, directing laterally, abutting the proximal margin of the peristome.Adeonella jahanai sp.nov.resembles A. extensa Harmer, 1957 in having narrow branches, gonozooids along the margin of branches, and slightly longer frontal avicularia, and in generally lacking vicarious avicularia near branch bifurcations, but differs from the latter in the direction of the frontal avicularia, and in having gonozooids with a non-tubular peristome, with the peristomial spiramen being very closely situated to the secondary orifice.

Distribution
Japan: Nansei islands (near Yakushima and west of okinawa), at depths of 37-95 m.

Remarks
Canu & Bassler (1929) originally described Adeona arculifera from Jolo and sulade islands, sulu Archipelago, Philippines, on the basis of the single spiramen, although the branched colony resembles the condition in Adeonellopsis.Harmer (1957) then transferred the species to Adeonellopsis on the basis of the operculum, which is not widely sinuate.Adeonellopsis arculifera resembles A. subsulcata (smitt, 1873) in the arrangement of the suboral avicularia but differs from the latter in having a circular spiramen in the center of the frontal shield.

Distribution
Adeonellopsis arculifera has previously been reported from the Philippines, indonesia, and the indian ocean, at depths of 38-53 m. in Japan, it has been detected only in the southwestern region, from Okinawa and near Yakushima Island, at depths of 47-88 m.Although this is the first Recent record for Japan, Hayami (1971)

Remarks
Ortmann (1890) first described Adeonellopsis japonica as Adeonella japonica, based on Döderlein's specimens from sagami Bay.Hayward (1988) discussed this species in his revision of Adeonella, though he did not examine Ortmann's material; he argued that Adeonella japonica almost certainly belongs in Adeonella because of the elongate avicularia along the edge of the branches, as described by ortmann.However, the frontal shield of A. japonica is umbonuloid, rather than the lepralioid frontal shield characteristic of Adeonella; therefore, A. japonica clearly belongs in Adeonellopsis.Harmer (1957) reported a Japanese adeonid species resembling Adeonellopsis parvipuncta MacGillivray (1886), which has two kinds of spiramina: a small, undivided, slightly denticulate single pore, or a much larger pore region comprising many pores.These features of the spiramen completely correspond to the spiramina of autozooids and gonozooids in A. japonica.Harmer (1957) noted that a few zooids in the middle of the branches have a larger spiramen, which is the condition of gonozooids in A. japonica.Furthermore, his sketch of the larger zooid also indicates a broader, slightly curved orifice.I thus consider Harmer's A. parvipuncta to be a synonym of A. japonica.

Remarks
ortmann (1890) reported this species as Adeonella tuberculata (Busk, 1884) from sagami Bay based on Döderlein's specimens, as it has two small avicularia between the orifice and spiramen.Adeonellopsis pentapora is quite small and fragile compared to the other adeonid species collected from sagami Bay; it also occupies unstable substrates such as hydroid stems (Fig. 11B) and gastropod shells (Fig. 11A).sakakura (1935) also reported a colony encrusting a gastropod shell from Toyama Bay.A colony of A. pentapora in the Döderlein collection is encrusted on a small shell of a dead gastropod inhabited by a hermit crab, and a colony collected from sagami Bay in 2002 is encrusted on a different species of small shell of a dead gastropod.Canu & Bassler (1929) reported Adeonellopsis pentapora from a broad area of the Indo-Pacific, including Japan (Tsugaru Strait).Harmer (1957) considered Adeonellopsis pentapora and A. tuberculata to be junior synonyms of Adeonellopsis yarraensis (Waters, 1881) based on having two small suboral avicularia and narrow branches.A. yarraensis, however, is currently regarded as a strictly fossil species and A. tuberculata as a recent species in Australia; therefore, i consider A. pentapora to be a valid species.

Remarks
ortmann's specimens comprise only the basal, anastomosed parts of colonies (Fig. 8A), and zooidal characters in these specimens are identical to those in the basal parts of the more-complete Adeonellopsis sparassis colonies that i studied.Adeonellopsis sparassis resembles A. sulcata (Milne edwards, 1836) in having a multiporous spiramen and small, distally directed suboral avicularia, but differs from the latter in having a smaller, circular spiramen.MacGillivray's (1880: plate 48, fig.7) illustration of Eschara mucronata (MacGillivray, 1868) (= A. sulcata) appears to represent the basal part of a European Journal of Taxonomy 203: 1-41 (2016) colony of Adeonellopsis that resembles A. sparassis.However, as I did not examine MacGillivray's type specimen, i do not include it in the synonymy of A. sparassis.
I identified an encrusting colony in the Emperor Showa collection as a young colony of A. sparassis based on the small, round multiporous spiramen and the triangular suboral avicularium between the ascopore and orifice.Hayward & McKinney (2002) described a similar ancestrular complex consisting of six zooids in the closely related encrusting genus Reptadeonella.Bock & Cook (2000) also reported a similar encrusting ancestrular complex in Adeonellopsis, but they described a remarkably different bipolar ancestrular colony in the articulated genus Adeona.I conclude the ancestrular complex in the emperor showa collection to be A. sparassis rather than Reptadeonella or the other genera, based on the orifice shape and the multiporous spiramen.The knobs on the frontal shield of zooids in the encrusting colony appear to be a character common to young zooids in several adeonid species.okada (1920) described another adeonid bryozoan, Adeonella hexangularis okada, 1920, from Misaki (sagami Bay) and the Kagoshima Gulf (southern Kyushu), which surely is Adeonellopsis according to his description of a multiporous spiramen.Due to the limited original description and apparent loss of the type specimens, the identity of A. hexangularis is unclear, but okada's description of an anastomosed colony morphology, frontal shields with a single or double rows of marginal pores, and gonozooids located at branch bifurcation and having a broad, proximodistally compressed orifice indicate that it is conspecific with A. sparassis and constitutes a junior synonym of the latter.Mawatari (1952) reported nominal A. hexangularis from off Wakayama and Minabe, Kii Peninsula, without a description; according to this record, A. sparassis is probably also distributed around the Kii Peninsula.

Distribution
Japan: detected in this study from sagami Bay, Tokyo Bay (Yokohama), sagami sea (izu Peninsula), Ariake sea, Nansei islands (near Yakushima and west of okinawa), and ogasawara, at depths of 24-141 m. it was collected from eastern sagami Bay and western sagami sea by Döderlein and emperor showa, but was not found recently in those areas by NsMT.

Diagnosis
Colony dichotomously branching; branches flat, roughly 3-4 mm wide.Autozooids oval, distinct, delineated by a deep groove; with a single row of marginal pores.Frontal shield smooth or slightly granulated.Peristome deep, oval.Spiramen monoporous.Two to six tiny pores in frontal wall proximal to orifice.Suboral avicularia triangular, small, almost same size as spiramen; in center of frontal shield, distal to spiramen, directed distally.Triangular marginal vicarious avicularia present.Gonozooids slightly broader than autozooids; orifice broad, proximodistally compressed, with slightly convex proximal margin; spiramen and avicularia almost same size as in autozooids.

Etymology
The specific name derives from the Latin parvus (small) and rostrum (used as a noun in apposition), referring to the small rostrum of the suboral avicularia.

Remarks
Adeonellopsis parvirostrum sp.nov.fits the original description of Adeonellopsis japonica in having a small, circular spiramen and small suboral avicularium, but its avicularium is much smaller than in the latter.Young autozooids of A. parvirostrum sp.nov.lack the striation perpendicular to the margin seen on the rim of young zooids of A. japonica.Adeonellopsis parvirostrum sp.nov.resembles A. lichenoides in the basal part of the colony (compare Fig. 5D with Fig. 15B), but differs from the latter in the presence of a distally directed suboral avicularium between the orifice and spiramen in older parts of branches.some small frontal avicularia are sparsely surrounded by the remains of associated areolae of original autozooids and/or kenozooids (Fig. 15A-C).some of the specimens of A. parvirostrum sp.nov.I observed were pinkish, although this may have resulted from artificial staining of another organism, as other bryozoan colonies in the same bottle were also pinkish.

Distribution
Japanese Pacific waters: north of Hachijo-jima Island, Sagami Sea, and near Amami Oshima, at depths of 135-213 m.

Remarks
Adeonellopsis toyoshioae sp.nov.resembles A. subteres (römer, 1863) in the number of alternate zooidal rows, raised margin of the frontal shield, and a large ascopore occupying a broad area of the frontal shield (Römer, 1863: pl.XXXV, fig.6).However, A. subteres was originally reported as a fossil from Germany and occurs in the eocene (Canu 1907;Braga 1963) and oligocene (David & Pouyet 1968) deposits of europe.i therefore concluded that A. toyoshioae sp.nov.represents a new species.Moreover, the recent European Journal of Taxonomy 203: 1-41 (2016) Adeonellopsis distoma (Busk, 1858) from the eastern N Atlantic is closely related to both species; Adeonellopsis distoma resembles A. toyoshioae sp.nov. in having a subtubular peristome and a large area of multiporous spiramen consisting of about seven pores.Adeonellopsis distoma, however, differs from A. toyoshioae sp.nov. in having an elongated spiraminal area, with usually two rows of pores, in having larger suboral avicularia and fewer zooidal rows comprising the branches, and in lacking the marginal umbos.Adeonellopsis toyoshioae sp.nov.also resembles A. sparassis in having a multiporous ascopore with more than four denticulate pores, and a single suboral avicularium extending over the proximal margin of the orifice.However, the ascopore in A. toyoshioae sp.nov. is not circular as in A. sparassis and occupies a much larger area of the frontal shield. in addition, A. toyoshioae sp.nov.has branches less than 2.0 mm wide, whereas those in A. sparassis are usually wider than 2.5 mm.Finally, the suboral avicularium is often directed slightly distolaterally in A. toyoshioae sp.nov., whereas it points directly distally A. sparassis.
The marginal umbos evident on younger zooids in A. toyoshioae sp.nov.are identical in size to those in A. pentapora; these umbos are also a characteristic feature of younger zooids in these species.

Distribution
Japanese Pacific waters: north of Hachijo-jima Island, southwest of Kochi Prefecture, and the northern Nansei islands (near Amami oshima and Tanegashima); at depths of 118-200 m.Hayami (1971) reported this species from fossiliferous sandstone in the Pliocene shinzato Tuff (shinzato Formation) on okinawa island, which is close to the recent distribution in Japan.
6. suboral avicularia small, single or paired ………Adeonellopsis pentapora Canu & Bassler, 1929 -suboral avicularium large, single ……………………………………………………………………7 HIROSE M., Japanese adeonid bryozoans Adeonellopsis pentapora is also thought to be widely distributed, occurring in the eastern Pacific from Tasmania to Japan.Mature colonies of A. pentapora are small and often occur as epibionts on substrata such as hydroid stems and gastropod shells inhabited by living hermit crabs.some hydroids can potentially inhabit soft bottoms, providing substrate for other organisms, and hermit crabs are at least more mobile than sessile bryozoan colonies, which might explain A. pentapora having the broadest distribution in Japan among the adeonids treated in this study (Fig. 18).Adeonellopsis japonica also appears to be widely distributed, occurring along the Pacific coast of Japan and having been reported from Hawaii, more than 6000 km distant; i did not detect any morphological differences between Japanese and Hawaiian specimens, but genetic studies are needed to clarify whether these populations are cryptic or invasive species.
in Japan, adeonid bryozoans have not been found north of Tsugaru strait, lying between Hokkaido and Honshu (Fig. 18).This pattern may be correlated with the warm Kuroshio Current and its branches (the Tsushima and Tsugaru Currents), and limited in the north by the cold oyashio Current (Fig. 1).
The lack of records from western Hokkaido despite the extension of the Tsushima current might be due to decreasing effects of the current and colder temperatures, but might also be due to a general lack of collecting in this area, especially in deeper water.Although the Pacific coast of Tohoku (northern Honshu) is influenced by the Oyashio Current, two species (A.japonica and A. pentapora) occur at otsuchi; this is presumably due to the effects of the Kuroshio and Tsugaru currents, which normally affect nearshore areas more than does the oyashio Current.

HIROSE M., Japanese adeonid bryozoans
Adeonellopsis pentapora shows the broadest distribution in Japan, from south of Yakushima to otsuchi (this study) and Tsugaru strait (Canu & Bassler 1929); the paucity of records of A. pentapora from the sea of Japan is probably due to low sampling effort in this area.Most other adeonid species are distributed in southern Japan, from central Honshu to some point in the Nansei islands.Adeonella jahanai sp.nov.and Adeonellopsis arculifera, detected only from the Nansei islands, show the narrowest distributions (Fig. 18).
in the present study, Adeonellopsis toyoshioae sp.nov.was collected from both temperate and subtropical habitats, in areas strongly influenced by the Kuroshio Current.Hayami (1971) described a typically Indo-Pacific bryozoan fauna from the Miocene to Pliocene Shinzato Tuff in Okinawa, where she reported fossil colonies of A. toyoshioae sp.nov., indicating a temperate to subtropical paleoenvironment in this area at the time.
Adeonellopsis japonica is distributed from Kouchi to Otsuchi on the Pacific side of Shikoku and Honshu, but unlike the other species is conspicuously absent from Kyushu and the Nansei islands (Fig. 18).Although A. japonica has also been reported from Hawaii (Cheetham et al. 1980

Fig. 1 .
Fig. 1.Maps showing the localities where adeonid bryozoans were collected.A. Collecting localities around Japan.Gray arrows indicate warm currents, the unfilled arrow indicates the cold current.B. Enlargement from previous, showing the localities around Sagami Bay, Sagami Sea, and Hachijo-jima island.C. enlargement from map A, showing the localities along the Nansei islands, from Tanegashima to okinawa.
DiagnosisColony dichotomously branching; branches narrow, about 1.2-2.5 mm wide.Autozooids oval or hexagonal, distinct, delineated by deep groove.Frontal shield entirely covered with minute granules, with more than 10 circular or slit-like areolar pores.Peristome deep, secondary orifice circular, primary reported a fossil specimen from the Pleistocene ryukyu Limestone of Kikai-jima, Kagoshima.
: UsNM 271601, iZ cat 8450; rB 8450), the records there are from deep water (549-605 m).This species thus appears to be distributed in cooler water than the other adeonid species.