WoRMS taxon details
Laetmonice uschakovi Jirkov, 1989
333751 (urn:lsid:marinespecies.org:taxname:333751)
accepted
Species
marine, brackish, fresh, terrestrial
recent only
Jirkov, I. A. (1989). [Bottom fauna of the USSR. Polychaeta]. Moscow: MGU Press. 141 p. [in Russian].
note: Offshore of Finnmark, Norway, Barents Sea, station 19 RV “Tunets”, cruise 105, 70.9667, 21.3833 (70°58’N, 21°23’E), depth 165-170 m [details]
note: Offshore of Finnmark, Norway, Barents Sea, station 19 RV “Tunets”, cruise 105, 70.9667, 21.3833 (70°58’N, 21°23’E), depth 165-170 m [details]
Holotype ZMUM NPL 772, geounit Russia
, Note Offshore of Finnmark, Norway, Barents Sea,...
Holotype ZMUM NPL 772, geounit Russia [details]
From editor or global species database
Type locality Offshore of Finnmark, Norway, Barents Sea, station 19 RV “Tunets”, cruise 105, 70.9667, 21.3833 (70°58’N, 21°23’E), depth 165-170 m [details]
Description [Part two of Laetmonice uschakovi Jirkov, 1989 description in Jirkov (2001: 111) translated by Elena Kupriyanova]
Description [Part one of Laetmonice uschakovi Jirkov, 1989 description in Jirkov (2001: 111) translated by Elena Kupriyanova in 2025]
Etymology The species is named after Pavel Vladimirovich Uschakov
Description [Part two of Laetmonice uschakovi Jirkov, 1989 description in Jirkov (2001: 111) translated by Elena Kupriyanova]
3. After the description of L. uschakovi had been published, we examined additional specimens of both this species and of L. filicornis. As it usually happens in such cases, the differences between the two species based on meristic characters turned out to be less pronounced: the gap in the number of CS became smaller, while the number of elytrae even overlaps in the two species. This makes identification more problematic, but it does not make us doubt that the these are two distinct species. Although L. uschakovi is a relatively larger species – it has a higher number of CS and pairs of elytrae - there is no significant correlation between these characters and worm body size in the studied size range (see graphs). If a worm has a segment which should bear elytrae, they are usually present (although elytrae maybe absent on the very last of such segments), thus, the number of pairs of elytrae reliably correlates with the number of CS in both species.
4. In the North Atlantic Laetmonice producta Grube, 1877seems to be widely distributed. Based on literature data (i. e., Chambers, 1985), specimens of this species of the same body length has one additional elytra-bearing segment and the total number of segments in this species is also higher (43-45).
Material. 23 samples (259 specimens) from collections of department of hydrobiology and ZMUM (Zoological Museum of Moscow University), besides, over 100 specimens missing labels from the teaching collection of department of hydrobiology. 130-530 m, 2.68°C -9.48° C.
Graphs – relationship of body length (X axis), and number of elytrae and number of CS (Y axis) in Laetmonice sp.
[details]
3. After the description of L. uschakovi had been published, we examined additional specimens of both this species and of L. filicornis. As it usually happens in such cases, the differences between the two species based on meristic characters turned out to be less pronounced: the gap in the number of CS became smaller, while the number of elytrae even overlaps in the two species. This makes identification more problematic, but it does not make us doubt that the these are two distinct species. Although L. uschakovi is a relatively larger species – it has a higher number of CS and pairs of elytrae - there is no significant correlation between these characters and worm body size in the studied size range (see graphs). If a worm has a segment which should bear elytrae, they are usually present (although elytrae maybe absent on the very last of such segments), thus, the number of pairs of elytrae reliably correlates with the number of CS in both species.
4. In the North Atlantic Laetmonice producta Grube, 1877seems to be widely distributed. Based on literature data (i. e., Chambers, 1985), specimens of this species of the same body length has one additional elytra-bearing segment and the total number of segments in this species is also higher (43-45).
Material. 23 samples (259 specimens) from collections of department of hydrobiology and ZMUM (Zoological Museum of Moscow University), besides, over 100 specimens missing labels from the teaching collection of department of hydrobiology. 130-530 m, 2.68°C -9.48° C.
Graphs – relationship of body length (X axis), and number of elytrae and number of CS (Y axis) in Laetmonice sp.
[details]
Description [Part one of Laetmonice uschakovi Jirkov, 1989 description in Jirkov (2001: 111) translated by Elena Kupriyanova in 2025]
Description [Part one of Laetmonice uschakovi Jirkov, 1989 description in Jirkov (2001: 111) translated by Elena Kupriyanova in 2025]
Laetmonice uschakovi Jirkov, 1989
Laetmonice uschakovi Jirkov, 1989:46-47, fig. 9, type locality: holotype from the station 19 RV “Tunets”, cruise 105, 70°58’N, 21°23’E, depth 165-170 m, 02.07.1978, deposited in ZMUM (not sure which museum it is) N Pl 772, 79 paratypes from south-western part of the Barents Sea and the adjacent regions of the Norwegian Sea, depth 155-525 m, bottom water temperature 2.2 – 7.0°C (18 samples deposited in ZMUM N Pl1773-Pl1790).
Laetmonice sp. – Uschakov, 1982:56-57, Table IV; Detinova, 1985b: 98.
Laetmonice filicornis – Zatsepin, 1948: 106; Hartmann-Schroeder, 1971: 41; 1996: 36-37, abb. 8 (partim) – non Kinberg, 1855.
Figure legend. Laetmonice uschakovi : 1 – anterior end, ventral view (text in the top left corner: peristomium = CS1; text below the image: elytrophores; text of the right: CS2 ); 2 - elytrae-bearing parapodia; 3 – antennae-bearing parapodia; distal end of harpoon-shaped notochaeta; 5 – neurochaeta (from Jirkov, 1989)
Description
Palps very long, attached below and laterally to basis of the lobe covered with papillae. Basis of this lobe covered with two short outgrowths and slightly annulated ceratophore positioned above and between the outgrowths. Ceratostyle very long, thin. A pair of unpigmented ommatophores positioned laterally at the antennal basis. 17 (rarely 18) pairs of brown elytrae on chaetigerous segments (CS) CS-2, CS-4, CS-5, and then on every second CS until CS25, after that on every third CS until CS37, which bears the 17th pair of elytra. Parapodia of the last CS can be poorly developed. Notochaetae needle-shaped on segments bearing elytra and harpoon-shaped on segments bearing antennae. Segments with antennae, in addition to needle-shaped notochaetae, bear relatively short capillary (hair-shaped) ones, sometimes forming poorly developed felt that does not even cover parapodia. Few neurochaetae, their distal parts with numerous hairs and one (rarely 2) spurs. Specimens 19-67 mm long are usually composed of 40-42 CS.
Etymology. The species is named after Pavel Vladimirovich Uschakov
Biology and distribution. Shelf Atlantic species. Liley widely distributed in the North Atlantic, in our samples found from the Newfoundland Bank to the Barents Sea. Found south of Iceland by Detinova (1985b).
Remarks.
1. The species was described but not named by Uschakov 1982)
2. Data on L. filicornis distribution in the Barents Sea given by Zatsepin (1948) in reality refer to that of L. uschakovi , while distribution of L. filicornis s. str. is described in that paper under the name Hermione hystrix (Savigny, 1818). The latter species is not known with certainty to inhabit the Arctic Ocean. Likely, many records of L. filicornis from the Arctic Ocean in reality are records of L. uschakovi. For example, L. filicornis sensu Hartmann-Schroeder (1971; 1996), judging by the description, probably is a mix of L. filicornis and L. uschakovi.
[continued in part two]
[details]
Laetmonice uschakovi Jirkov, 1989
Laetmonice uschakovi Jirkov, 1989:46-47, fig. 9, type locality: holotype from the station 19 RV “Tunets”, cruise 105, 70°58’N, 21°23’E, depth 165-170 m, 02.07.1978, deposited in ZMUM (not sure which museum it is) N Pl 772, 79 paratypes from south-western part of the Barents Sea and the adjacent regions of the Norwegian Sea, depth 155-525 m, bottom water temperature 2.2 – 7.0°C (18 samples deposited in ZMUM N Pl1773-Pl1790).
Laetmonice sp. – Uschakov, 1982:56-57, Table IV; Detinova, 1985b: 98.
Laetmonice filicornis – Zatsepin, 1948: 106; Hartmann-Schroeder, 1971: 41; 1996: 36-37, abb. 8 (partim) – non Kinberg, 1855.
Figure legend. Laetmonice uschakovi : 1 – anterior end, ventral view (text in the top left corner: peristomium = CS1; text below the image: elytrophores; text of the right: CS2 ); 2 - elytrae-bearing parapodia; 3 – antennae-bearing parapodia; distal end of harpoon-shaped notochaeta; 5 – neurochaeta (from Jirkov, 1989)
Description
Palps very long, attached below and laterally to basis of the lobe covered with papillae. Basis of this lobe covered with two short outgrowths and slightly annulated ceratophore positioned above and between the outgrowths. Ceratostyle very long, thin. A pair of unpigmented ommatophores positioned laterally at the antennal basis. 17 (rarely 18) pairs of brown elytrae on chaetigerous segments (CS) CS-2, CS-4, CS-5, and then on every second CS until CS25, after that on every third CS until CS37, which bears the 17th pair of elytra. Parapodia of the last CS can be poorly developed. Notochaetae needle-shaped on segments bearing elytra and harpoon-shaped on segments bearing antennae. Segments with antennae, in addition to needle-shaped notochaetae, bear relatively short capillary (hair-shaped) ones, sometimes forming poorly developed felt that does not even cover parapodia. Few neurochaetae, their distal parts with numerous hairs and one (rarely 2) spurs. Specimens 19-67 mm long are usually composed of 40-42 CS.
Etymology. The species is named after Pavel Vladimirovich Uschakov
Biology and distribution. Shelf Atlantic species. Liley widely distributed in the North Atlantic, in our samples found from the Newfoundland Bank to the Barents Sea. Found south of Iceland by Detinova (1985b).
Remarks.
1. The species was described but not named by Uschakov 1982)
2. Data on L. filicornis distribution in the Barents Sea given by Zatsepin (1948) in reality refer to that of L. uschakovi , while distribution of L. filicornis s. str. is described in that paper under the name Hermione hystrix (Savigny, 1818). The latter species is not known with certainty to inhabit the Arctic Ocean. Likely, many records of L. filicornis from the Arctic Ocean in reality are records of L. uschakovi. For example, L. filicornis sensu Hartmann-Schroeder (1971; 1996), judging by the description, probably is a mix of L. filicornis and L. uschakovi.
[continued in part two]
[details]
Etymology The species is named after Pavel Vladimirovich Uschakov
Etymology The species is named after Pavel Vladimirovich Uschakov [details]
Read, G.; Fauchald, K. (Ed.) (2026). World Polychaeta Database. Laetmonice uschakovi Jirkov, 1989. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=333751 on 2026-02-21
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Nomenclature
original description
Jirkov, I. A. (1989). [Bottom fauna of the USSR. Polychaeta]. Moscow: MGU Press. 141 p. [in Russian].
note: Offshore of Finnmark, Norway, Barents Sea, station 19 RV “Tunets”, cruise 105, 70.9667, 21.3833 (70°58’N, 21°23’E), depth 165-170 m [details]
note: Offshore of Finnmark, Norway, Barents Sea, station 19 RV “Tunets”, cruise 105, 70.9667, 21.3833 (70°58’N, 21°23’E), depth 165-170 m [details]
Taxonomy
redescription
Jirkov, I.A. (2001). [Polychaeta of the Arctic Ocean] (In Russian) Polikhety severnogo Ledovitogo Okeana. Yanus-K Press, Moscow, 632 pp., available online at https://www.researchgate.net/publication/259865957_Jirkov_2001_Polychaeta_of_the_North_Polar_Basin
page(s): 111; note: See English translation description attached as two notes [details] Available for editors
[request]
page(s): 111; note: See English translation description attached as two notes [details] Available for editors
[request]
Present Present in aphia/obis/gbif/idigbio Inaccurate Introduced: alien Containing type locality
Holotype ZMUM NPL 772, geounit Russia [details]
From editor or global species database
Description [Part two of Laetmonice uschakovi Jirkov, 1989 description in Jirkov (2001: 111) translated by Elena Kupriyanova]3. After the description of L. uschakovi had been published, we examined additional specimens of both this species and of L. filicornis. As it usually happens in such cases, the differences between the two species based on meristic characters turned out to be less pronounced: the gap in the number of CS became smaller, while the number of elytrae even overlaps in the two species. This makes identification more problematic, but it does not make us doubt that the these are two distinct species. Although L. uschakovi is a relatively larger species – it has a higher number of CS and pairs of elytrae - there is no significant correlation between these characters and worm body size in the studied size range (see graphs). If a worm has a segment which should bear elytrae, they are usually present (although elytrae maybe absent on the very last of such segments), thus, the number of pairs of elytrae reliably correlates with the number of CS in both species.
4. In the North Atlantic Laetmonice producta Grube, 1877seems to be widely distributed. Based on literature data (i. e., Chambers, 1985), specimens of this species of the same body length has one additional elytra-bearing segment and the total number of segments in this species is also higher (43-45).
Material. 23 samples (259 specimens) from collections of department of hydrobiology and ZMUM (Zoological Museum of Moscow University), besides, over 100 specimens missing labels from the teaching collection of department of hydrobiology. 130-530 m, 2.68°C -9.48° C.
Graphs – relationship of body length (X axis), and number of elytrae and number of CS (Y axis) in Laetmonice sp.
[details]
Description [Part one of Laetmonice uschakovi Jirkov, 1989 description in Jirkov (2001: 111) translated by Elena Kupriyanova in 2025]
Laetmonice uschakovi Jirkov, 1989
Laetmonice uschakovi Jirkov, 1989:46-47, fig. 9, type locality: holotype from the station 19 RV “Tunets”, cruise 105, 70°58’N, 21°23’E, depth 165-170 m, 02.07.1978, deposited in ZMUM (not sure which museum it is) N Pl 772, 79 paratypes from south-western part of the Barents Sea and the adjacent regions of the Norwegian Sea, depth 155-525 m, bottom water temperature 2.2 – 7.0°C (18 samples deposited in ZMUM N Pl1773-Pl1790).
Laetmonice sp. – Uschakov, 1982:56-57, Table IV; Detinova, 1985b: 98.
Laetmonice filicornis – Zatsepin, 1948: 106; Hartmann-Schroeder, 1971: 41; 1996: 36-37, abb. 8 (partim) – non Kinberg, 1855.
Figure legend. Laetmonice uschakovi : 1 – anterior end, ventral view (text in the top left corner: peristomium = CS1; text below the image: elytrophores; text of the right: CS2 ); 2 - elytrae-bearing parapodia; 3 – antennae-bearing parapodia; distal end of harpoon-shaped notochaeta; 5 – neurochaeta (from Jirkov, 1989)
Description
Palps very long, attached below and laterally to basis of the lobe covered with papillae. Basis of this lobe covered with two short outgrowths and slightly annulated ceratophore positioned above and between the outgrowths. Ceratostyle very long, thin. A pair of unpigmented ommatophores positioned laterally at the antennal basis. 17 (rarely 18) pairs of brown elytrae on chaetigerous segments (CS) CS-2, CS-4, CS-5, and then on every second CS until CS25, after that on every third CS until CS37, which bears the 17th pair of elytra. Parapodia of the last CS can be poorly developed. Notochaetae needle-shaped on segments bearing elytra and harpoon-shaped on segments bearing antennae. Segments with antennae, in addition to needle-shaped notochaetae, bear relatively short capillary (hair-shaped) ones, sometimes forming poorly developed felt that does not even cover parapodia. Few neurochaetae, their distal parts with numerous hairs and one (rarely 2) spurs. Specimens 19-67 mm long are usually composed of 40-42 CS.
Etymology. The species is named after Pavel Vladimirovich Uschakov
Biology and distribution. Shelf Atlantic species. Liley widely distributed in the North Atlantic, in our samples found from the Newfoundland Bank to the Barents Sea. Found south of Iceland by Detinova (1985b).
Remarks.
1. The species was described but not named by Uschakov 1982)
2. Data on L. filicornis distribution in the Barents Sea given by Zatsepin (1948) in reality refer to that of L. uschakovi , while distribution of L. filicornis s. str. is described in that paper under the name Hermione hystrix (Savigny, 1818). The latter species is not known with certainty to inhabit the Arctic Ocean. Likely, many records of L. filicornis from the Arctic Ocean in reality are records of L. uschakovi. For example, L. filicornis sensu Hartmann-Schroeder (1971; 1996), judging by the description, probably is a mix of L. filicornis and L. uschakovi.
[continued in part two]
[details]
Etymology The species is named after Pavel Vladimirovich Uschakov [details]
Type locality Offshore of Finnmark, Norway, Barents Sea, station 19 RV “Tunets”, cruise 105, 70.9667, 21.3833 (70°58’N, 21°23’E), depth 165-170 m [details]
