Nannoniscus oblongus Sars 1870
Nannoniscus oblongus Sars, 1870 (Figs 2–6) Nannoniscus oblongus Sars, 1870: 164; Sars, 1897 a: 119, pl. 50 (partim); Hansen, 1916: 92 –94, pl. VIII, fig. 4 a– 4 f; Gurjanova, 1932: 53, table XVIII, 68; Wolff, 1962: 262. Not Nannoniscus oblongus : Menzies, 1962: 136 –137. Material examined. Zoologica...
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Online Access: | https://dx.doi.org/10.5281/zenodo.5621389 https://zenodo.org/record/5621389 |
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openpolar |
institution |
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DataCite Metadata Store (German National Library of Science and Technology) |
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Biodiversity Taxonomy Animalia Arthropoda Malacostraca Isopoda Nannoniscidae Nannoniscus Nannoniscus oblongus |
spellingShingle |
Biodiversity Taxonomy Animalia Arthropoda Malacostraca Isopoda Nannoniscidae Nannoniscus Nannoniscus oblongus Wilson, George D. F. Nannoniscus oblongus Sars 1870 |
topic_facet |
Biodiversity Taxonomy Animalia Arthropoda Malacostraca Isopoda Nannoniscidae Nannoniscus Nannoniscus oblongus |
description |
Nannoniscus oblongus Sars, 1870 (Figs 2–6) Nannoniscus oblongus Sars, 1870: 164; Sars, 1897 a: 119, pl. 50 (partim); Hansen, 1916: 92 –94, pl. VIII, fig. 4 a– 4 f; Gurjanova, 1932: 53, table XVIII, 68; Wolff, 1962: 262. Not Nannoniscus oblongus : Menzies, 1962: 136 –137. Material examined. Zoological Museum of Oslo "Ex Coll. G. O. Sars, Nannoniscus oblongus G. O. Sars ", no indication of locality or collection date: ZMO # 10107, intact female on slide, Fig. 4 A–D; ZMO # 10108, dissected parts on slide, Figs 4 E, 5 A–E. Hjeltefjord, coll. by R.R. Hessler, J. O. Strömberg, near 60 ° 40 'N 4 ° 54 'E (position from gazetteer): 4. vii. 1978, RothlisbergPearcy sled, 260 m, 3 females, 1 female (Fig. 6; AM P. 74561), 1 male (Figs 2–3, AM P. 74562); 7–8. vii. 1978, Beyer 1 net sled, 260 m, 1 female. Remarks on material examined. Sars (1870; 1897 a) did not establish types for his species, but Museum material exists that might have been used for his descriptions. Two female specimens were borrowed from the Zoological Museum of Oslo and are reillustrated here. Although these specimens are listed as "Ex G. O. Sars collection", whether or not they were used in his description is uncertain. The ZMO specimens illustrated here (Figs 4–5) do not precisely match those of Sars (1897 a: pl. 50, upper female), and they lack locality data. Consequently, no lectotype designation can be made using these specimens. Without any certainty that the "Sars collection" specimens are from the type locality, naming a neotype is also unwarranted. Diagnosis. Body broadly oval in dorsal view. Head lateral margins broadly curved and narrowing anteriorly, without projecting anterior spines. Pereonites 1–4 anterolateral angles with small setae, 2 with largest seta; 1 distinctly shorter that other pereonites, 1–4 increasing in length posteriorly; 4 lateral margin broadly convex, widest anteriorly; 5 lateral margin medially linear, not strongly angled to midline; 7 lateral margin distinctly shorter than 5–6 lateral margins; 6–7 ventral midline with rounded lobes in lateral view, posterior lobe largest. Pleotelson broader than head width; posteriorly rounded, without posterolateral spines, without indentation above uropods. Antennula article 2 distal margin with 3 blunt projections bearing penicillate setae. Antenna article 3 scale without basal articulation, spinelike, elongate, extending beyond distal margin of article 4; flagellum with 10 articles in female, 8 in male. Pereopods II–VII ventral dactylar ("accessory") claw robust, basally as wide as dorsal claw. Pleopod I of male lateral margin nearly straight, narrowing posteriorly; distal tip lateral lobes projecting beyond margin, angular, with narrower proximal neck, medial lobes broadly rounded, distally curving ventrally, margin with elongate fine setae increasing in length medially. Pleopod II of male endopod distal article length 0.85 protopod length. Pleopod II of female broadly rounded posteriorly, midline with posteroventrallydirected curved spine; midline posterior to spine concave in lateral view. Uropods inserting on ridge anterior to anus, adjacent to but not covering anus; exopod distinctly longer than protopod. Remarks. The type species of Nannoniscus Sars, 1870, N. oblongus is distinctive in that it has a large anterolaterally directed spine on antennal article 3 in the position of antennal scale (Figs 2 A–B, 4 A). This spine is mentioned in Sars's (1870: 164) description. Nannoniscus oblongus is most similar to N. caspius Sars, 1897 b; these two species share a broad body, the antennular article 3 spine and strong ventral claws on the pereopodal dactyli. N. caspius , however, has an angular tip to the pleotelson, a posteriorly curved ventral spine on pereonite 7 and a broader body than N. oblongus . The concept of N. oblongus was confounded in Sars (1897 a), in which a female of another species was shown as a male. Hansen (1916) corrected this by transferring Sars's "male" to Nannoniscus crassipes , which was subsequently assigned to Rapaniscus Siebenaller & Hessler (1981). Collections made in Hjeltefjord (Norway) by R.R. Hessler & J. O. Strömberg included a fully mature male of N. oblongus that shows the essential features of a male Nannoniscus (Figs 2, 3). Hansen (1916, pl. VIII, 4 a–f) illustrated specimens from Ingolf samples, which agree with specimens illustrated here. The taxon N. oblongus appears to be widespread in the North Atlantic and Arctic Basins, ranging from coastal fjords of Norway and Spitzbergen to the Arctic Ocean and Iceland (Wolff 1962; Svavarsson et al, 1997). Subtle differences between the male illustrated here and those of Hansen (1916), e.g., tip of the pleopod I and shape of the pleotelson, may signal the presence of a species complex, of which N. caspius would be a member. Menzies (1962 a: fig. 31 I –K) records a female specimen from off Argentina, (LGO Biotrawl 212, 44 °53.3'S, 51 °26.5'W, 5843 m) but only copied Hansen's (1916) figures and didn't illustrate his specimen. Notably, Menzies (1962: 136) does not mention the distinctive antennal spine in his species diagnosis. This specimen from the South Atlantic is almost certainly not N. oblongus , although it should be checked. The diagnosis above is based on the study of the Sars collection specimens (two females and the Hjeltefjord specimens). Given the detailed similarity between the females from the Sars collection and those from Hjeltefjord (Figs. 4, 6), I am confident that they all at least represent the same general taxon, N. oblongus . The diagnosis includes characters that were found to vary in Nannoniscus species. The male pleopods are illustrated only irregularly in the literature, but they almost certainly provide rich detail for distinguishing species. The male pleopod I presents two different lateral outlines in ventral view (Fig. 3 A–B). When the pleopod is in situ , the medial margin of the second pleopod overlaps a thin lateral border of the first pleopod, so that the latter is convexsided. The pleopod II of the mature male (Fig. 3 C–D) has an elongate stylet so that the entire article is 85 % the length of the protopod. Other species can be seen to have distinctly longer or shorter stylets, and the distal lateral and medial lobes of pleopod I vary considerably. As in the Desmosomatidae, nannoniscids vary in the setation and relative size of the pereopods, even within the genus Nannoniscus as currently defined. For example, some species, N. oblongus included, have a plesiomorphic form of the pereopod II–VII dactylar claws wherein the ventral claw is more robust although shorter than the dorsal claw. Deepsea species, such as N. meteori , show a ventral claw reduced to practically a thin seta in species like N. cristatus Mezhov, 1986 or N. inermis Hansen, 1916, or a thin flat triangular plate (Fig. 7 B arrow) as in Rapaniscus dewdneyi Siebenaller & Hessler, 1981. The full range of variation is unknown so to define homologous states probably requires a synoptic survey of all species. Body shape and ventral spination also need to be thoroughly studied across Nannoniscus species to fully appreciate the phylogenetic patterns represented in this genus. : Published as part of Wilson, George D. F., 2008, A review of taxonomic concepts in the Nannoniscidae (Isopoda, Asellota), with a key to the genera and a description of Nannoniscus oblongus Sars, pp. 1-24 in Zootaxa 1680 on pages 14-16, DOI: 10.5281/zenodo.180391 : {"references": ["Sars, G. O. (1870) Nye dybvandscrustaceer fra Lofoten. Forhandlinger I Videnskabs-Selskabet I Kristiania, 1869, 145 - 286.", "Sars, G. O. (1897 a) Isopoda. Part VII, VIII. Desmosomidae, Munnopsidae. In: An account of the Crustacea of Norway with short descriptions and figures of all the species. Bergen Museum, Bergen, Norway, pp. 117 - 144.", "Hansen, H. J. (1916) Crustacea Malacostraca III: Isopoda. Danish Ingolf Expedition, 3 B, 1 - 262.", "Gurjanova, E. F. (1932) The Isopods from the Arctic. Analytical tables of the fauna of the U. S. S. R. Zoological Institute of the Academy of Sciences, Leningrad, 181 pp.", "Wolff, T. (1962) The systematics and biology of bathyal and abyssal Isopoda Asellota. Galathea Report, 6, 1 - 320.", "Sars, G. O. (1897 b) On some additional Crustacea from the Caspian Sea. Annales du Musee Zoologique Academie Imperiale des Sciences, St Petersbourg, 2, 273 - 305.", "Siebenaller, J. & Hessler, R. R. (1981) The genera of the Nannoniscidae (Isopoda, Asellota). Transactions of the San Diego Society of Natural History, 19, 227 - 250.", "Menzies, R. J. (1962 a) The zoogeography, ecology, and systematics of the Chilean marine isopods (Reports of the Lund University Chile Expedition 1948 - 49, no. 4). Lunds Universitets Arrskrifter N. F. Avd. 2, 57, 1 - 162.", "Mezhov, B. V. (1986) Bathyal and abyssal Nannoniscidae and Desmosomatidae (Isopoda, Asellota) from Alaska Bay. Archives of the Zoological Museum, Moscow State University, 24, 126 - 167."]} |
format |
Text |
author |
Wilson, George D. F. |
author_facet |
Wilson, George D. F. |
author_sort |
Wilson, George D. F. |
title |
Nannoniscus oblongus Sars 1870 |
title_short |
Nannoniscus oblongus Sars 1870 |
title_full |
Nannoniscus oblongus Sars 1870 |
title_fullStr |
Nannoniscus oblongus Sars 1870 |
title_full_unstemmed |
Nannoniscus oblongus Sars 1870 |
title_sort |
nannoniscus oblongus sars 1870 |
publisher |
Zenodo |
publishDate |
2008 |
url |
https://dx.doi.org/10.5281/zenodo.5621389 https://zenodo.org/record/5621389 |
long_lat |
ENVELOPE(9.895,9.895,63.645,63.645) ENVELOPE(61.911,61.911,-73.437,-73.437) |
geographic |
Arctic Arctic Ocean Lofoten Norway Argentina Bergen Seta Menzies |
geographic_facet |
Arctic Arctic Ocean Lofoten Norway Argentina Bergen Seta Menzies |
genre |
Arctic Arctic Ocean Iceland Lofoten North Atlantic Spitzbergen Alaska |
genre_facet |
Arctic Arctic Ocean Iceland Lofoten North Atlantic Spitzbergen Alaska |
op_relation |
http://publication.plazi.org/id/A623FF8D6F395E2EFFA1F666FFC3FFA4 https://zenodo.org/communities/biosyslit https://dx.doi.org/10.5281/zenodo.180391 http://publication.plazi.org/id/A623FF8D6F395E2EFFA1F666FFC3FFA4 https://dx.doi.org/10.5281/zenodo.180393 https://dx.doi.org/10.5281/zenodo.180394 https://dx.doi.org/10.5281/zenodo.180395 https://dx.doi.org/10.5281/zenodo.180396 https://dx.doi.org/10.5281/zenodo.180397 https://dx.doi.org/10.5281/zenodo.180398 https://dx.doi.org/10.5281/zenodo.5621388 https://zenodo.org/communities/biosyslit |
op_rights |
Open Access info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5281/zenodo.5621389 https://doi.org/10.5281/zenodo.180391 https://doi.org/10.5281/zenodo.180393 https://doi.org/10.5281/zenodo.180394 https://doi.org/10.5281/zenodo.180395 https://doi.org/10.5281/zenodo.180396 https://doi.or |
_version_ |
1766349839545663488 |
spelling |
ftdatacite:10.5281/zenodo.5621389 2023-05-15T15:19:38+02:00 Nannoniscus oblongus Sars 1870 Wilson, George D. F. 2008 https://dx.doi.org/10.5281/zenodo.5621389 https://zenodo.org/record/5621389 unknown Zenodo http://publication.plazi.org/id/A623FF8D6F395E2EFFA1F666FFC3FFA4 https://zenodo.org/communities/biosyslit https://dx.doi.org/10.5281/zenodo.180391 http://publication.plazi.org/id/A623FF8D6F395E2EFFA1F666FFC3FFA4 https://dx.doi.org/10.5281/zenodo.180393 https://dx.doi.org/10.5281/zenodo.180394 https://dx.doi.org/10.5281/zenodo.180395 https://dx.doi.org/10.5281/zenodo.180396 https://dx.doi.org/10.5281/zenodo.180397 https://dx.doi.org/10.5281/zenodo.180398 https://dx.doi.org/10.5281/zenodo.5621388 https://zenodo.org/communities/biosyslit Open Access info:eu-repo/semantics/openAccess Biodiversity Taxonomy Animalia Arthropoda Malacostraca Isopoda Nannoniscidae Nannoniscus Nannoniscus oblongus Taxonomic treatment article-journal Text ScholarlyArticle 2008 ftdatacite https://doi.org/10.5281/zenodo.5621389 https://doi.org/10.5281/zenodo.180391 https://doi.org/10.5281/zenodo.180393 https://doi.org/10.5281/zenodo.180394 https://doi.org/10.5281/zenodo.180395 https://doi.org/10.5281/zenodo.180396 https://doi.or 2022-02-08T12:40:44Z Nannoniscus oblongus Sars, 1870 (Figs 2–6) Nannoniscus oblongus Sars, 1870: 164; Sars, 1897 a: 119, pl. 50 (partim); Hansen, 1916: 92 –94, pl. VIII, fig. 4 a– 4 f; Gurjanova, 1932: 53, table XVIII, 68; Wolff, 1962: 262. Not Nannoniscus oblongus : Menzies, 1962: 136 –137. Material examined. Zoological Museum of Oslo "Ex Coll. G. O. Sars, Nannoniscus oblongus G. O. Sars ", no indication of locality or collection date: ZMO # 10107, intact female on slide, Fig. 4 A–D; ZMO # 10108, dissected parts on slide, Figs 4 E, 5 A–E. Hjeltefjord, coll. by R.R. Hessler, J. O. Strömberg, near 60 ° 40 'N 4 ° 54 'E (position from gazetteer): 4. vii. 1978, RothlisbergPearcy sled, 260 m, 3 females, 1 female (Fig. 6; AM P. 74561), 1 male (Figs 2–3, AM P. 74562); 7–8. vii. 1978, Beyer 1 net sled, 260 m, 1 female. Remarks on material examined. Sars (1870; 1897 a) did not establish types for his species, but Museum material exists that might have been used for his descriptions. Two female specimens were borrowed from the Zoological Museum of Oslo and are reillustrated here. Although these specimens are listed as "Ex G. O. Sars collection", whether or not they were used in his description is uncertain. The ZMO specimens illustrated here (Figs 4–5) do not precisely match those of Sars (1897 a: pl. 50, upper female), and they lack locality data. Consequently, no lectotype designation can be made using these specimens. Without any certainty that the "Sars collection" specimens are from the type locality, naming a neotype is also unwarranted. Diagnosis. Body broadly oval in dorsal view. Head lateral margins broadly curved and narrowing anteriorly, without projecting anterior spines. Pereonites 1–4 anterolateral angles with small setae, 2 with largest seta; 1 distinctly shorter that other pereonites, 1–4 increasing in length posteriorly; 4 lateral margin broadly convex, widest anteriorly; 5 lateral margin medially linear, not strongly angled to midline; 7 lateral margin distinctly shorter than 5–6 lateral margins; 6–7 ventral midline with rounded lobes in lateral view, posterior lobe largest. Pleotelson broader than head width; posteriorly rounded, without posterolateral spines, without indentation above uropods. Antennula article 2 distal margin with 3 blunt projections bearing penicillate setae. Antenna article 3 scale without basal articulation, spinelike, elongate, extending beyond distal margin of article 4; flagellum with 10 articles in female, 8 in male. Pereopods II–VII ventral dactylar ("accessory") claw robust, basally as wide as dorsal claw. Pleopod I of male lateral margin nearly straight, narrowing posteriorly; distal tip lateral lobes projecting beyond margin, angular, with narrower proximal neck, medial lobes broadly rounded, distally curving ventrally, margin with elongate fine setae increasing in length medially. Pleopod II of male endopod distal article length 0.85 protopod length. Pleopod II of female broadly rounded posteriorly, midline with posteroventrallydirected curved spine; midline posterior to spine concave in lateral view. Uropods inserting on ridge anterior to anus, adjacent to but not covering anus; exopod distinctly longer than protopod. Remarks. The type species of Nannoniscus Sars, 1870, N. oblongus is distinctive in that it has a large anterolaterally directed spine on antennal article 3 in the position of antennal scale (Figs 2 A–B, 4 A). This spine is mentioned in Sars's (1870: 164) description. Nannoniscus oblongus is most similar to N. caspius Sars, 1897 b; these two species share a broad body, the antennular article 3 spine and strong ventral claws on the pereopodal dactyli. N. caspius , however, has an angular tip to the pleotelson, a posteriorly curved ventral spine on pereonite 7 and a broader body than N. oblongus . The concept of N. oblongus was confounded in Sars (1897 a), in which a female of another species was shown as a male. Hansen (1916) corrected this by transferring Sars's "male" to Nannoniscus crassipes , which was subsequently assigned to Rapaniscus Siebenaller & Hessler (1981). Collections made in Hjeltefjord (Norway) by R.R. Hessler & J. O. Strömberg included a fully mature male of N. oblongus that shows the essential features of a male Nannoniscus (Figs 2, 3). Hansen (1916, pl. VIII, 4 a–f) illustrated specimens from Ingolf samples, which agree with specimens illustrated here. The taxon N. oblongus appears to be widespread in the North Atlantic and Arctic Basins, ranging from coastal fjords of Norway and Spitzbergen to the Arctic Ocean and Iceland (Wolff 1962; Svavarsson et al, 1997). Subtle differences between the male illustrated here and those of Hansen (1916), e.g., tip of the pleopod I and shape of the pleotelson, may signal the presence of a species complex, of which N. caspius would be a member. Menzies (1962 a: fig. 31 I –K) records a female specimen from off Argentina, (LGO Biotrawl 212, 44 °53.3'S, 51 °26.5'W, 5843 m) but only copied Hansen's (1916) figures and didn't illustrate his specimen. Notably, Menzies (1962: 136) does not mention the distinctive antennal spine in his species diagnosis. This specimen from the South Atlantic is almost certainly not N. oblongus , although it should be checked. The diagnosis above is based on the study of the Sars collection specimens (two females and the Hjeltefjord specimens). Given the detailed similarity between the females from the Sars collection and those from Hjeltefjord (Figs. 4, 6), I am confident that they all at least represent the same general taxon, N. oblongus . The diagnosis includes characters that were found to vary in Nannoniscus species. The male pleopods are illustrated only irregularly in the literature, but they almost certainly provide rich detail for distinguishing species. The male pleopod I presents two different lateral outlines in ventral view (Fig. 3 A–B). When the pleopod is in situ , the medial margin of the second pleopod overlaps a thin lateral border of the first pleopod, so that the latter is convexsided. The pleopod II of the mature male (Fig. 3 C–D) has an elongate stylet so that the entire article is 85 % the length of the protopod. Other species can be seen to have distinctly longer or shorter stylets, and the distal lateral and medial lobes of pleopod I vary considerably. As in the Desmosomatidae, nannoniscids vary in the setation and relative size of the pereopods, even within the genus Nannoniscus as currently defined. For example, some species, N. oblongus included, have a plesiomorphic form of the pereopod II–VII dactylar claws wherein the ventral claw is more robust although shorter than the dorsal claw. Deepsea species, such as N. meteori , show a ventral claw reduced to practically a thin seta in species like N. cristatus Mezhov, 1986 or N. inermis Hansen, 1916, or a thin flat triangular plate (Fig. 7 B arrow) as in Rapaniscus dewdneyi Siebenaller & Hessler, 1981. The full range of variation is unknown so to define homologous states probably requires a synoptic survey of all species. Body shape and ventral spination also need to be thoroughly studied across Nannoniscus species to fully appreciate the phylogenetic patterns represented in this genus. : Published as part of Wilson, George D. F., 2008, A review of taxonomic concepts in the Nannoniscidae (Isopoda, Asellota), with a key to the genera and a description of Nannoniscus oblongus Sars, pp. 1-24 in Zootaxa 1680 on pages 14-16, DOI: 10.5281/zenodo.180391 : {"references": ["Sars, G. O. (1870) Nye dybvandscrustaceer fra Lofoten. Forhandlinger I Videnskabs-Selskabet I Kristiania, 1869, 145 - 286.", "Sars, G. O. (1897 a) Isopoda. Part VII, VIII. Desmosomidae, Munnopsidae. In: An account of the Crustacea of Norway with short descriptions and figures of all the species. Bergen Museum, Bergen, Norway, pp. 117 - 144.", "Hansen, H. J. (1916) Crustacea Malacostraca III: Isopoda. Danish Ingolf Expedition, 3 B, 1 - 262.", "Gurjanova, E. F. (1932) The Isopods from the Arctic. Analytical tables of the fauna of the U. S. S. R. Zoological Institute of the Academy of Sciences, Leningrad, 181 pp.", "Wolff, T. (1962) The systematics and biology of bathyal and abyssal Isopoda Asellota. Galathea Report, 6, 1 - 320.", "Sars, G. O. (1897 b) On some additional Crustacea from the Caspian Sea. Annales du Musee Zoologique Academie Imperiale des Sciences, St Petersbourg, 2, 273 - 305.", "Siebenaller, J. & Hessler, R. R. (1981) The genera of the Nannoniscidae (Isopoda, Asellota). Transactions of the San Diego Society of Natural History, 19, 227 - 250.", "Menzies, R. J. (1962 a) The zoogeography, ecology, and systematics of the Chilean marine isopods (Reports of the Lund University Chile Expedition 1948 - 49, no. 4). Lunds Universitets Arrskrifter N. F. Avd. 2, 57, 1 - 162.", "Mezhov, B. V. (1986) Bathyal and abyssal Nannoniscidae and Desmosomatidae (Isopoda, Asellota) from Alaska Bay. Archives of the Zoological Museum, Moscow State University, 24, 126 - 167."]} Text Arctic Arctic Ocean Iceland Lofoten North Atlantic Spitzbergen Alaska DataCite Metadata Store (German National Library of Science and Technology) Arctic Arctic Ocean Lofoten Norway Argentina Bergen Seta ENVELOPE(9.895,9.895,63.645,63.645) Menzies ENVELOPE(61.911,61.911,-73.437,-73.437) |