As the result of the recent revision of Arctic Polychaeta, it have been found, that in some families near half of species had been identified erroneously and more than 10% species are new. Far Eastern fauna is known even worse. No wonder that in small collection have been found two new species of the single genus Ampharete: A.kudenovi and A.saphronovae. The first undoubtedly previously was mixed with A.finmarchica Sars, 1865 (= A.arctica Malmgren, 1866), co-occurring in the Far Eastern waters and sometimes in the same sample.
Material: 98 specimens stat. 21 R/V "Odyssey", cruise 33 (48°16'N 154°44' E, 140-150 m, 3/8/84), 22 (50°40'N 154°33' E, 1000 m, 6/8/84), cruise 34, stat. 12 (46°58'N 152°17 E, 450-480 m, 30/12/84) (collector M.V.Kolesnikov) and R/V "Vitjaz", stat. 3569 (39°44'N 142°18'E, 423 m). HOLOTYPE stat. 21 R/V "Odyssey", cruise 33.
Deposed at department of Hydrobiology, Moscow States University.
Description. Middle lobe rounded, there is glandular field along its posterior margin. Eyes absent. Buccal tentacles papillose. Paleae much longer and wider the most developed notosetae, turned anteriorly they at least achieve posterior margin of prostomium. Paleae are similar to A. finmarchica, but tips pointed somewhat more evenly. There are 6-15 paleal setae at each side (70% have 9-11). Amplitude of variation of paleal setae number of A.kudenovi almost completely overlap with A. finmarchica one (in 108 specimens 8-25). However Far Eastern A. finmarchica have more setae (14-25), thus almost there is no overlap. In both species number of paleal setae weakly correlated with body length. Paleal setae of A.kudenovi contrary to A. finmarchica ones are lighter, comparatively shorter and very seldom have broken tips. The distance between branchial groups varies form almost absent to equal diameter of branchophore. Places of attachment of three branchophores of each group from almost straight row. The forth attaches behind and between inner and middle ones, it distinctly connected with notopodia of 2 thoracic setiger (TS). Branchostyles are typical: smooth, irregularly wrinkled, turned behind they achieve 7-8 TS. There are a pair of small nephridial papillae near inner corners of inner branchophores bases, the similar papillae are behind notopodia of 3-5 TS. 14 TS, 12 last with neuropodia. 13 AU (abdominal uncinigers) (near 5% have 14 AU). Rudimental notopodia small, neuropodial cirri absent. Pigidium with two long lateral cirri and more or less developed numerous low papillae. Notosetae narrow bilimbate. Neurosetae of 3rd neuropodium: there are near 50 neurosetae, each with 5 teeth in profile, subrostral tooth single, others paired, the size of teeth increased apically; usually there is smaller unpaired apical teeth, totally there are 9-10 teeth. A.finmarchica has neurosetae of 3rd TS with 8 teeth in profile, all paired (in double rows), the size of teeth increased apically; usually there is big apical teeth, usually with small one; totally there are 15-16 teeth. Abdominal neurosetae of 1 AU are similar to thoracic ones, of last AU - avicular. Up to 26 mm long. Tube: translucent organic base is covered by particles of briozoans, shells, sea urchin needles, flat stones etc., without any trace of usual for ampharetid tubes mud or debrit.
Etymology. The species is named after Dr. Jerry D.Kudenov.
The difference from other species. The new species belong to group of species of Ampharete with stout paleal setae. Within the group it is most similar to A.finmarchica, differs as mentioned above by structure of tube, paleae and thoracic neurosetae. The usage of tube for species diagnostic can look doubtful, however investigated tubes of A.finmarchica s.str. from big collection (more than 10,000 specimens), collected from Newfoundland to the Japan Sea, including samples, where A.kudenovi have been found, were very monomorph and build from muddy-debrit, more or less incrustated in anterior part of tube with large sand grains. Among other species of the genus, only A.longipaleolata Uschakov, 1950 has 13 AU, this species can be easily differ by much bigger paleal setae.
Lysippe mexicana Fauchald, 1972 also has prostomium Ampharete-type, 4 pairs of branchiae, 12 uncinigerous TS and 13 AU. It differs from A.kudenovi by weakly developed paleae and presence of 15 TS.
Material. More than 1,000 specimens from 13 stations form the Sea of Ohotsk, Sakhalin,
Piltun bay (52°N 143°E). All samples were collected by helicopter from 3 m depth.
Collector Dr. N.E.Denisov. Holotype from station 35.
Deposed at the Department of Hydrobiology, Moscow States University.
Description. Middle lobe more or less pointed, twice longer width, usually there is a pair of small eyespots in the corner of its base. Buccal tentacles pinnate, pinnulae several times longer diameter of tentacle. Paleal setae with long slowly tapered tips, the same width and length as the most developed notosetae. Worms with body length 5-15 mm have 0-12 paleal setae (paleae are absent in 5% worms), in 85% - 6-10 paleal setae. Holotype has 8 setae in each group. The distance between branchial groups varies form almost absent to equal diameter of branchophore. Places of attachment of three branchophores of each group from almost straight row. The forth attaches behind and between inner and middle ones, it distinctly connected with notopodium of 2 TS. Branchophores joined to body wall at bases only, their distal parts are free and form high transverse ridge. Branchostyles are typical: smooth to irregularly annulated. There are a pair of small nephridial papillae near inner corners of inner branchophores bases. 14 (very seldom 15) TS, 12 last with neuropodia. Last 1-2 pairs of notopodia often are distinctly less, the last can even absent. 14 AU. Podial cirri and rudimental notopodia are absent. Pigidium with two short lateral cirri and numerous papillae. Notosetae narrow bilimbate. Neurosetae of 3rd neuropodium: there are near 20 neurosetae, each with 5-6 teeth in profile, all paired (in two rows) as exception neurosetae with single teeth in third row between those two can present. Paratypes 5-15 mm long, holotype - 13 mm. Tube thin walled (thickness of walls in order less inner diameter) muddy, incrustated with sand grains, it surface is smooth, sand grains do no prominent.Etymology. The species is named after M.A.Saphronova.
The difference from other species. There is no Ampharete species with 14 AU.
Taxonomic remarks. The absence of paleae in part of population of A.saphronovae is not ugliness in any case. Contrary, the absence can be completely explain as individual variation of meristic character (number of paleal setae) with small average number and wideness of diapason enough for part of population has 0 (zero) paleal setae. In connection with this it is necessary to re-weight absence-presence of paleae as of the main generic character in ampharetid taxonomy. It is obviously, if a character varies intraspecific, it can not and should not be used for separation of genera. As the only difference between Asabellides (6 nominal species) from Ampharete (more than 30 species) - the absence of paleae in the first, there is no base to take them as separate any longer.
Additional argument for decreasing of rank of character "absence-presence of paleae" is that within the single genus paleae can vary very much. The bigger genus the more variation. It seems illogical to evaluate extreme variant of cline in separate genera. One can found such clines within all three big ampharetid genera. The most amplitude and more complete row we can see within Ampharete. A. longipaleolata Uschakov, 1950 possesses the most developed paleae, several times longer body width. Some species (A. finmarchica, A. goeesi Malmgren, 1866, A. kudenovi and others) paleal setae distinctly less than in A. longipaleolata, but nevertheless much bigger the most developed notosetae. In A. crassiseta Annenkova, 1929 and A. saphronovae paleal setae near equal to notosetae or somewhat less them. Species of Asabellides are situated on margin of this cline. There is analogical row in other big genus - Amphicteis. The most of species have big paleae, distinctly bigger notosetae. In A. foliata Haswell, 1883 and A. philippinarum Grube, 1878 paleal setae much less the most developed notosetae. At least Amphicteis angustifolia (Grube, 1878) has no palea at all (and in this case species without paleae have been separated in monotypic genus Paramphicteis Caullery, 1944). The similar situation take place in last big genus - Amage Malmgren, 1866. The genus is characterised by absence of paleae, and for 2 species with paleae (much smaller the most developed notosetae) have been established separate genus Amagopsis Pergament et Chlebovitch in Chlebovitch, 1964.
Emended diagnosis of Ampharete is given below.
Type species: Amphicteis acutifrons Grube, 186O.
Prostomium without glandular ridges and nuchal organs, trilobed, middle lobe anteriorly rounded. Buccal tentacles papillose. 1 pair of nephridial papillae near medial pair of branchiae. There are no neither modified notopodia nor transversal ridges in anterior or posterior part of thorax. Paleae from huge to completely absent. 12 uncinigerous TS. Characteristic number of AU 12-13. Thoracic neurosetae usually with two rows of teeth.
Puc. 1 Ampharete kudenovi sp.n., paratype: A - anterior body, dorsally, Á - tip of paleal seta; B - neuroseta of 3 TS in face and profile; A.finmarchica (48°15'N 141°05'E, 650 m): Ã - tip of paleal seta; Ä - neuroseta of 3 TS in face and profile. Scale: A - 1 mm, Á,Ã - 0.1 mm; B, Ä - 0.05 mm.
Puc. 2 Ampharete saphronovae sp.n., paratype:
A - anterior body, dorsally, Á
- tip of paleal seta; B - neurosetae of 3 TS (the same specimen)
face and profile.
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