Sea stars of the genus Henricia Gray, 1840 (Echinodermata, Asteroidea) from Vostok Bay, Sea of Japan

We report seven species of the genus Henricia Gray, 1840 that were found in Vostok Bay, and two species from adjacent area, known from museum collection or seen in underwater footage. while existing literature reported no confirmed species from this area. Most of these species: H. djakonovi, H. alexeyi, H. densispina, H. hayashii, H. granulifera, H. pacifica, H. asiatica, and H. oculata robusta were reported from the Sea of Japan previously. H. nipponica, known from Japan, is reported from Russian seas for the first time. All studied taxa are re-described here using a range of morphological characters and partial 16S rRNA nucleotide sequences, life colorations of several species are reported for the first time, and an identification key is provided. Lectotype designations are fixed for studied series of species described by AM Djakonov.

Comprehensive accounts of the Vostok Bay marine biota began following the construction of the Vostok Marine Biological Station in 1970. The station was established by the Soviet Academy of Sciences and was a significant research site used by many Russian and USSR biologists. The echinasterids of this region have been overlooked. In recent literature, the reviews on echinoderm fauna of Vostok Bay (Dautov & Tyurin, 2014) and of adjacent Far Eastern National Marine Reserve (Lebedev, 2015), this family was represented by ''Henricia sp.'' only. Earlier literature review of Peter the Great Bay biota (with relevant section based on Djakonov (1961) reported seven Henricia species (Adrianov & Kussakin, 1998). Thereby, the fauna of Henricia of Vostok Bay remains totally unknown except for a single Henricia sp. of 21 species potentially inhabiting the Sea of Japan (Smirnov, 2013). Recent studies reported detailed morphology of 13 species from the Sea of Japan (Shin & Ubagan, 2015a;Shin & Ubagan, 2015b;Ubagan & Shin, 2016;Chichvarkhin, 2017a;Chichvarkhin, 2017b;Chichvarkhin & Chichvarkhina, 2017a;Chichvarkhin & Chichvarkhina, 2017b) and adjacent waters of Yellow Sea (Xiao, Liao & Liu, 2011).
Many sea stars including the species of the genus Henricia are a popular objects in biochemical and biomedical research because of perspective drugs found in these animals (e.g., Fedorov et al., 2008;Utkina, 2009). Taxonomic confusions have prevented confident identifications for Henricia, which has limited potential applications for this research field. Recent studies of coastal marine benthic fauna of Russian Pacific shores revealed numerous previously overlooked species belonging to different taxonomic groups (e.g., Chichvarkhin et al., 2016;Ekimova et al., 2016;Temereva & Chichvarkhin, 2017), hence a discovery of new species in a poorly studied and confused group like the Echinasteridae in Vostok Bay remains possible. Therefore, this study aims to shed light to Henricia fauna occurring in Vostok Bay by delineating putative species by the means of DNA barcoding, then finding corresponding morphological characters that are diagnostic for identification.

MATERIAL AND METHODS
Observations and sample collections were made by SCUBA-diving in 2014 through 2017 in Vostok Bay of the Sea of Japan (Fig. 1). Most of the individuals belonging to abundant species were returned and released where each was collected. The images were taken with a Nikon D810 or D7000 cameras and a Nikkor 60/2.8 lens. Also, remotely controlled submersible apparatus Obzor-150 was used in 2015 at the depth of 45 m at the silty outer part of the bay. The specimens were preserved in 96% ethanol or dry with prominent portion of a ray preserved in separate vials in 96% ethanol and deposited in the Museum of National Science Center of Marine Biology, Russian Academy of Sciences (Vladivostok, Russia). Skeletal plates and spines were denuded using 5-15% sodium hypochlorite solution at room temperature. Scanning electron images of the spines were obtained using Zeiss Sigma and Zeiss Evo electron microscopes after carbon coating. Studied specimens are preserved in the collections of Zoological Institute of Russian Academy of Sciences, St. Petersburg, Russia (voucher code ZIN ), National Science Center of Marine Biology, Russian Academy of Sciences (voucher code MIMB) and Hokkaido University, Sapporo, Japan (voucher code ZIHU ). Sequenced specimens are listed in the Table 1. DNA was extracted using the Diatom TM DNA Prep 100 kit (Isogene Lab, Moscow, Russia) according to the manufacturer's protocol. Partial sequence for mitochondrial 16S rRNA gene (16S) was used in this study. This fragment was used as a good species-specific marker in several Henricia and echinoderm studies (Chichvarkhin & Chichvarkhina, 2017b). The primers 16Sar and 16Sbr (Palumbi, 1996) were used to amplify the region of interest. Polymerase chain reaction amplifications were carried out in a 20-µL reaction volume, which included 4 µL of 5× Screen Mix by Eurogen Lab We also attempted unsuccessfully to amplify the portion of the mitochondrial gene for cytochrome c oxidase subunit I (COI) that is commonly used in metazoan DNA barcoding. The primers normally employed by Folmer et al. (1994) do not work well for echinasterids. We also attempted unsuccessfully to amplify the portion of the mitochondrial gene for cytochrome c oxidase subunit I (COI) that is commonly used in metazoan DNA barcoding. The master mix for each sample was prepared using 34.75 µL H 2 O, 5.00 µL PCR Buffer (Evrogen, Moscow, Russia), 5.00 µL 25 mM MgCl 2 , 1.00 µL 40 mM dNTPs, 1.00 µL 10 mM primer 1, 1.00 µL primer 2, 0.25 µL 5 mg/ml (10×) Taq (Evrogen, Moscow, Russia), and 1.00 µL extracted DNA. Amplification began with an initial denaturation for 1 min at 95 • C followed by 40 cycles of 15 s at 95 • C, 15 s at 52 • C, 30 s at 72 • C with a final extension of 7 min at 72 • C. Sequencing for both strands proceeded with the Big Dye v3.1 sequencing kit by Applied Biosystems. Sequencing reactions were analyzed using ABI 3130 and 3500 Genetic Analyzer (Applied Biosystems, Foster City, CA, USA) in National Scientific Center of Marine Biology (Vladivostok, Russia). The sequences were aligned with ClustalW software (Larkin et al., 2007). Tree-based methods for species delineation and identification were used, including the calculation of pairwise p-distances (i.e., the proportion of variable positions) and neighbor-joining (NJ) clustering using MEGA7 software (Kumar, Stecher & Tamura, 2016). The primers normally employed by Folmer et al. (1994) do not work well for echinasterids. Recent works (Laakmann et al., 2016;Layton, Corstorphine & Hebert, 2016) have demonstrated that the COI can distinguish some entities in the Echinasteridae. Knott, Ringvold & Blicher (2017) used Henricia-specific primers more successfully: they delimited almost all north Atlantic species, although we failed to amplify any product using these primers. Often, the COI can be poorly or not amplified with 'Folmer's' primers (Folmer et al., 1994) commonly used in metazoan DNA barcoding, hence we are considering the 16S is a more robust and preferable marker for routine DNA barcoding of Asteroidea (Chichvarkhin, 2017b;Chichvarkhin, 2017b;Knott, Ringvold & Blicher, 2017). Recently, Knott, Ringvold & Blicher (2017) have developed Henricia-specific primers to amplify the COI. Amplified fragment was same informative as the 16S, hence we see no reason to use it as a marker in our study.
In his descriptions of Henricia species, Alexander M. Djakonov (Djakonov, 1948;Djakonov, 1958) never designated type materials; the specimens that we identified in ZIN collection by the labels written by him and his co-worker Zoya I. Baranova, and collection dates preceding a publication. Certain of these syntypes series contain or may contain specimens belonging to different species, so we have fixed a particular syntype as the lectotype in such cases, with all other specimens in each series becoming paralectotypes.
For the taxa below, the author (Djakonov, 1958;Djakonov, 1961) did not designate unique specimens as the holotypes according to International Code of Zoological Nomenclature (ICZN) Article 73.1.3, i.e., the series of the syntypes were used for description. For all these species, we identified the specimens marked as the ''holotypes'' in ZIN collection. But this method for a holotype fixation applied by Z.I. Baranova is incorrect according to ICZN Article 72.4.7, since these specimens unequivocally belong to the type series according to ICZN Article 72.4.1.1. To avoid confusion, here we are fixing unique specimens as the lectotypes of several of Djakonov's taxa based on the specimens used in this study. Appropriate lectotypes designations are given in species sections below. We disregarded ''holotype'' labels later added to particular syntype specimens in the ZIN collection in the hand-writing of Djakonov
Ventrolateral row consists of densely set oval plates. Second ventrolateral row extends to a half of ray length, consists of tiny round plates. Ventrolateral pseudopaxillae bear 3-5 spines in one row. Adambulacrals with 3-4 larger near-furrow spines and three small spines in one Deep furrow spine small, single. Oral plates each bear single apical, three marginal, and two suboral spines.
Color in life varies greatly from red to orange. Some specimens with broad darker areas on rays or almost white on disc and proximally on rays (Fig. 3). Anal area darker or same color as background; madreporite lighter or same color as background. Actinal side uniformly orange.
Ventrolateral plates sub-quadrate, smaller than inferomarginals. Pseudopaxillae bear 4-5 spines in one row. Adambulacrals with three larger thick near-furrow spines and four smaller spines in one row. Deep furrow spine thick, single. Oral plates each bear single apical, three large marginal, and three suboral spines.
Color, in life, bloody-red with light whitish tint proximally on rays and on disc, also on ray tips in some specimens (Figs. 4A-4D). Anal area not discernible from background; madreporite yellow. Actinal side uniformly orange.
Ecology: inhabits open bays exposed to wave activity at 15 m depths.
Superomarginal row poorly discernible, consists of plates similar to adjacent aborals, bearing 3-5 spines, same as abactinal spines, arranged in one row. Intermarginal row extended to a half of ray length; plates with 4-5 spines in one row. Plates of intermarginal and adjacent marginal rows connected by additional transversal plates. Inferomarginal plates large, transversally elongated, pseudopaxillae bear 8-10 spines in one transversal row.
Ventrolateral plates pillow-shaped, with proximal outgrowth overlaying next proximal plate; pseudopaxillae bear 4-7 spines in one transversal row. Second ventrolateral row consists of smaller round plates bearing 2-3 spines; this row extends to a half of ray length. Adambulacrals with 3-4 larger near-furrow spines and 6-8 smaller spines in two irregular rows (Fig. 5C). Deep furrow spine small, single. Oral plates not fused, each bear single apical, four marginal, and four suboral blunt spines.
Color in life. Abactinal side dirty-orange to brown, actinal side orange, lighter than abactinal side (Fig. 5A). Anal area darker than background; madreporite light creamy.
Ecology: The species was found on rocky substrates at the depths of 1-20 m at water temperature of 2-22 • C .
Distribution. Abundant in the northern part of Japan (Hayashi, 1940). Reported here from Russian waters for the first time.
Superomarginal row bent dorsally at ray base ( Fig. 1C), consists of T-shaped plates with central dorsal outgrowth overlapping adjacent abactinal plates; bear 8-10 spines arranged in 2 rows. In large specimen, two complete or qincomplete intermarginal rows consisting of rod-shaped plates that connected to adjacent marginal rows with similar rod-shaped transversal plates crowned with 6-8 spines in two rows; one of intermarginal row extended to or beyond half ray. In this way, supero-and inferomarginal rows in some specimens (e.g., MIMB-33214, Fig. 1C) are widely separated with two intermarginal rows and two series of additional transversal plates. But in most specimens (Fig. 3D) intermarginal rows and connecting plates are less developed. Inferomarginal row extended over entire ray length, its pseudopaxillae bear 14-20 spines in two transversal rows. Ventrolateral quadratic plates bear 10-13 relatively small spines in 2-3 rows. Second ventrolateral row consists of about 18 transversally elongated rod-shaped plates with low tubercle. Arched adambulacrals with slightly curved small furrow spine, one large slightly flattened to spatulate spine (Figs. 1C, 1D) faced into furrow (but in some individuals, more than one spine is spatulate, Fig. 3F); the other 3-5 gradually smaller spines faced ventrally in one staggered row bearing numerous thorns on apices. Spatulate shape varies because it is constituted by soft tissue, not spine itself. Oral plates not fused, bear 4 marginal and 1-4 suboral spines.
Ecology. Living sea stars were found off Mednyi Island on rock at depths 5-10 m at water temperature of 4 • C. Probably, they fed on yellow colored sponge, which was detected nearby (Figs. 2E, 2F). In other areas, found at depths >100 m feeding on sponges, detritus, hydrozoans, and bryozoans (Jewett et al., 2015); brooding (Jewett et al., 2015).
Color in life. Abactinal side brown with spine apices orange (Fig. 6A); marginal rows brown as aboral side; ventrolateral, adambulacral, oral and furrow areas orange (Fig. 6B). Anal area small and lighter than background; madreporite bright orange.
Ecology. A single specimen of this species was found on rocky substrate at the depth of 15 m at water temperature of 16 • C.

Subgenus Setihenricia Chichvarkhin & Chichvarkhina, 2017
Type species Henricia hayashii Djakonov, 1961  Type locality: Rudnaya Bay, Sea of Japan, Russia We identified H. pseudoleviuscula specimen in ZIN collection labeled as the ''holotype'' presumably by Z.I. Baranova. We are designating this specimen as lectotype of Henricia pseudoleviuscula (Djakonov, 1958 Chichvarkhin & Chichvarkhina (2017a) and Chichvarkhin & Chichvarkhina (2017b) described this species as one of two 'tiger-striped' sympatric morphs that co-occur in the northwestern Sea of Japan, while the other form was incorrectly referred to as H. pseudoleviuscula. This study found that both morphotypes had identical sequences, so they more likely represent discontinuous phenotypes of the same species (Fig. 2); both forms cannot be referred as H. pseudoleviuscula (Djakonov, 1961) because the lectotype of the latter possesses very different spines (Figs. 7K, 7L), similar to those of H. reniossa Hayashi, 1941 (Fig. 7M). Thus, our amended description of H. djakonovi here is expanded to include H. pseudoleviuscula sensu (Chichvarkhin, 2017a).
Superomarginal row bent dorsally at ray base, consists of square pillow-shaped plates. Inferomarginals and ventrolaterals are similarly pillow-shaped. Intermarginal rows consisting of usually one, but up to six, irregular shaped plates, constituting a proximal intermarginal area that provides an inflation of ray base. Superomarginals bear 20-35 spines, same as abactinal spines, arranged in four rows. Inferomarginal row extended over entire ray length (Fig. 7B), its pseudopaxillae bear 30-45 spines in 4-6 transversal rows.
Color in life. Rays brownish-orange, abactinal side of the disc dark (Fig. 7C). Anal area almost black; madreporite partially creamy, partially brownish. In ethanol-preserved specimens, the madreporite is the same color as abactinal side of disc. Abactinal side of rays marked with dark brown to black spots of irregular shape, some of them look like broad transversal lines. Actinal side is uniformly colored orange-red, same as abactinal background color of rays.
Ecology. The species was found on rocky substrates at the depths of 1-20 m at water temperature 2-22 • C. In aquarium conditions, some were (one was?) kept over 10 months in an aquarium without any macroscopic food supply, which could indicate that they survived by grazing microscopic food, such as encrusting protists or diatoms.
Ventrolateral plates small, oval; pseudopaxillae bear 10 spines in two irregular rows. Adambulacrals with four larger near-furrow spines and eight smaller spines in two rows  8F). Deep furrow spine small, single, double at distal quarter of ray in some specimens. Oral plates each bear single apical, three marginal, and 1-2 suboral spines.
Ecology: The species was found on rocky substrate at the depth of 5-20 m at water temperature 16 • C.
Distribution. Known for the northwestern part of the Sea of Japan (Djakonov, 1961). Morphologically similar H. reniossa asiatica (Djakonov, 1958) was described from the northwestern shore of the Sea of Japan (Dzhygit Bay). Known specimens of this H. reniossa asiatica possess similar tightly meshed skeleton with distinct ridges on the inferomarginal plates as in H. hayashii. But it is significantly larger than any H. hayashii specimen that we ever studied (R = 142 mm), and possesses very unusually shaped aboral spines with blunt apex and a number of tiny denticles on it (Fig. 8N).
We identified the specimen imaged on fig. 54 of Djakonov (1961) in Henricia hayashii description in ZIN collection, it was labeled as the ''holotype'' presumably by ZI Baranova (Fig. 8). We found that this specimen does not possess double deep ambulacral spines (Fig. 8M) as described by Djakonov (1961). Also, we found a specimen identified by Djakonov as H. hayashii with two deep adambulacral spines (Fig. 8N) conforming the original diagnosis. It was the only one specimen with broken ray tip from Moneron Island, i.e., this is the only specimen in which deep spines might be counted earlier by Djakonov and/or Baranova: it is nearly impossible to observe these spines in an undamaged specimen. Therefore, we suppose that double deep adambulacral spine is not a distinctive character in this species, e.g., it is also specific for H. densispina (Sladen, 1878). All studied specimens from continental shore of the Sea of Japan possess single deep spine. Here, we are designating one of these specimens as the lectotype of Henricia hayashii (Djakonov, 1961): ZIN -4/6038, South off Povorotnyi Cape, Sea of Japan, Russia, 21 Aug 1930, 44 m, leg. Shurin. 8. Henricia asiatica Djakonov, 1958 (Fig. 9; Supplemental Information 1, first sea star: 1-5th s) Henricia reniossa asiatica Djakonov, 1958: 303-305, fig. 14;1961: 22, pl. 2, fig. 11, pl. 12, figs. 52-53.
Henricia asiatica -Chichvarkhin & Chichvarkhina, 2017a: 208, Fig. 4B; Chichvarkhin & Chichvarkhina, 2017b: 25. Type locality: Dzhygit Bay, Tatar Str., Sea of Japan, Russia. We found a specimen (Fig. 9) in ZIN collection identified as H. reniossa asiatica and labeled as the ''holotype''. We are designating this specimen as the lectotype of Henricia reniossa asiatica (Djakonov, 1958). R = 142 mm, r = 16 mm; ZIN -2/12820, Opposite Dzhygit Bay, Tatar H. reniossa asiatica), had been recorded with the use of remotely controlled submersible apparatus south-east off the outer part of Vostok Bay (opposite Passek Cape, 42 • 44.6 N 132 • 43.8 E) at the depth of 45 m (appendix 1). R of the largest individual is about 90-100 mm, aboral coloration dark orange/mahogany. One of these specimens was associated with with a large mussel, Crenomytilus grayanus (Dunker, 1853), probably filtering plankton from water currents generated by the mollusk. Brun (1976) reported observations interpreted as suspension feeding in Henricia species, hypothesizing that some Henricia species may engage in rheophilic feeding behavior, i.e., collecting suspended phytoplankton in water currents generated by the sponges. If further supported, this could explain why Henricia individuals are often encountered sitting on the sponges, which has often led to an assumed sponge diet. However, most sponges feed on microbial cells, so it remains to be demonstrated that any Henricia could capture such tiny food items. However, we never observed suspension feeding behavior of any Henricia as Rasmunsen (1965) reported for H. sanguinolenta (O.F. (Müller, 1776). Suspension feeding on phytoplankton is a possible feeding strategy at shallow water habitats but is poorly effective at the depths >100 m, hence this species is likely polyphagous even if they feed on phytoplankton at shallower depths.
Marginal rows irregular proximally, after a half of ray length well discernible. Superomarginal row, consists of plates similar but slightly larger than adjacent aborals, bearing about 25 spines, same as abactinal spines, arranged in four irregular rows. Intermarginal row extended to full ray length; plates with about 20 spines in one row. Plates of intermarginal row oval, smaller than superomarginals. Inferomarginal plates relatively large, transversally elongated, with ridges. pseudopaxillae bear 30-35 spines in 4-5 irregular rows.
Ventrolateral plates round or oval; pseudopaxillae bear about 20 spines in four irregular rows. Adambulacrals with three larger near-furrow spines and 8-9 smaller spines in three rows (Fig. 9F). Deep furrow spine small, single but double at ray tip (Figs. 10N, 10O). Oral plates each bear single apical, four marginal, and three suboral spines.
Color in life. Abactinal and actinal sides bright orange (Figs. 10A, 10B). Anal area darker than background; madreporite light creamy. Light yellow to orange at near-furrow area.
Ecology. The species was found on rocky substrate at the depth of 10 m at water temperature 20 • C.
Distribution. Known from the northwestern part of the Sea of Japan and South China Sea (Xiao, Liao & Liu, 2011) and Japan (Hayashi, 1940). Similar species previously reported  (Hayashi, 1940;Djakonov, 1961) and probably from South China Sea (Xiao, Liao & Liu, 2011) belong to a distinct species possessing very fine slender spines crowned with 3 long thorns, while in H. densispina the spines are stouter (Xiao, Liao & Liu, 2011). The specimens from Vostok Bay also resemble H. leviuscula dyscrita (Fisher, 1911) described from California. This name was reported by Djakonov (1948) from the western Pacific, Okhotsk Sea. Later, he did not mention this name in his publications. We found three specimens in ZIN collection identified as H. leviuscula dyscrita, but later they were re-identified as H. tacita Djakonov, 1958. We compared these specimens with the specimen ZIN-14/12800 marked as ''H. tacita holotype'' presumably by Z.I. Baranova after A.M. Djakonov's death (although the holotype was not designated for this name by the author): this specimen from Aniva Bay, off Sakhalin Island possess less discernible superomarginal plates, the ridges on proximal marginal plates, and wider rays than re-identified exemplars from Okhotsk Sea, i.e., this specimen strikingly resembles H. reniossa Hayashi, 1940 described from northern Japan, although these two species possess very distinctive abactinal spines. There are four extra ''H. leviuscula dyscrita det. Djakonov'' specimens from Okhotsk are listed in ZIN catalogue (ZIN-4/3453 and ZIN-10/8450) collected by Ushakov in 1932, but we did not succeed in finding them. All these specimens are likely the syntypes of H. tacita Djakonov, 1958. To avoid future confusion, we are designating the lectotype for H. tacita Djakonov, 1958 with the specimen ZIN-14/12800 because it fully conforms to Djakonov's original diagnosis and photographed specimen (Djakonov, 1961: Pl. 11, fig. 44).
The specimens from Vostok Bay are different from all specimens mentioned above. They do not possess crescent-shaped pseudopaxillae and smaller papular areas, i.e., do not belong to H. tacita or H. leviuscula dyscrita.
apparatus, although trawling in this area did not allow us to collect any Henricia species. Just three species were found in periodically desalted (32 to 2 ) inner part of the bay, while the others were strictly associated with always highly mineralized (appr. 32 ) outer part, and occurred on mainly rocky bottoms but sometimes on a silty substrate.  H. (H.) alexeyi Chichvarkhin & Chichvarkhina, 2017a;Chichvarkhin & Chichvarkhina, 2017b DISCUSSION Smirnov's (2013) review of the invertebrates of Russian Pacific waters estimates that there are 21 echinasterid species reported from the Sea of Japan. Some of them were confirmed to the eastern part of that sea (H. aniva Djakonov, 1958, H. pseudoleviuscula Djakonov, 1958, H. sachalinica Djakonov, 1958, H. tacita Djakonov, 1958, H. orientalis Djakonov, 1950. Some of the listed species are dubious reports, including some that were likely misidentified (H. spiculifera Clark, 1901, H. aspera robusta Djakonov, 1948. Occurrence of deep-water H. reniossa asiatica Djakonov, 1961, which very likely is a distinct species related to a shallow-water H. reniossa Hayashi, 1940, is possible in Peter the Great Bay but we did not find it in Vostok Bay, probably because we focused mostly on shallow depths. Therefore, the total number of species that we have confirmed for Vostok Bay or its vicinity is estimated to be less than or about 15 species. Several Henricia species are known from adjacent waters of Korea and Japan, e.g. H. ohshimai Hayashi, 1940, H. reniossa Hayashi, 1940, H. nipponica Uchida, 1928, so they could also be found here.

Key to the genus Henricia of Vostok Bay
In general, Henricia sea stars are common in Vostok Bay. However, H. djakonovi dominates among the others making about 80% of found individuals (Chichvarkhin, 2017a). The second abundant species is H. nipponica (about 15% of found individuals), while the others are rather rare ( Table 2). The H. densispina, H. hayashii, and H. granulifera were encountered within this study just once despite the fact that the two latter species were found abundant in Rudnaya Bay, where water salinity is high and remains stable throughout the year. We hypothesize that most Henricia species are intolerant of decreased salinity in the inner part of Vostok Bay, and are restricted to the outer bay where the salinity was closer to oceanic. All species treated here inhabit near-shore rocky areas, with none found on the shallow silty bottom that completely occupies the central part of Vostok Bay and its inner part. The only exceptions were two remotely-recorded exemplars from deeper water on a silty bottom.

CONCLUSIONS
This study revealed seven Henricia species that inhabit Vostok Bay, with two additional species suspected as present but not yet sampled. All these species can be clearly identified with DNA barcoding approach using 16S rRNA marker. Morphological characters are also very valuable for identification of most species. Vostok Bay does not constitute a good habitat for high Henricia species diversity because of relatively low salinity water, especially in summer time, less than 30 m depths, and silty bottoms. However, a discovery of a few overlooked species remains possible along the outer shore of the bay.