Difference between revisions of "Sternaspis scutata"

Latest revision as of 09:52, 8 April 2013

Taxonavigation

Ordo: Canalipalpata
Familia: Sternaspidae
Genus: Sternaspis

Name

Sternaspis scutata (Ranzani, 1817) emended – Wikispecies link – Pensoft Profile

• Thalassema scutatus Ranzani, 1817: 1458–1462, Pl. 11, figs 10–13.
• Sternaspis scutata Claparède 1869^[1]: 95–96, Pl. 31, fig. 9; Rietsch 1882^[2]: 1–84, Pls. 18–23; Fauvel 1927^[3]: 216–218, fig. 76; 1934^[4]: 60; Townsend et al. 2006^[5]: 282–284, figs 1–2.

Type material

Eastern Mediterranean Sea, Aegean Sea. Neotype (RBCM 005-140-001) and 9 paraneotypes (RBCM 005-140-002), Turkey, Izmar Bay, 38°30'00"N, 26°50'00"E, 33 m, 11-VII-2000.
Additional material. Aegean Sea, Turkey. 14 spec. (RBCM 005-139-001), Izmar Bay, 38°30'N, 26°50'E, 33 m, 11-VII-200. Croatia. 7 spec. (ECOSUR 2645), Rovigno d'Istria, VI-1983, J. Vidakovic & D. Zavodnik, coll. 2 spec. (ECOSUR 2646), off Rijeka, X-1981, P. Gillet, coll. 2 spec. (ECOSUR 2647), Rovigno d'Istria (no further data). France. 2 spec. (ZMA 1374), Bretagne. Italy. 8 spec. (MNHL 766), Gulf of Naples, 1888. Five spec. (ZMA 1373), Naples, 1893. 3 spec. (ZMA 1372), Triest. Five spec. (ZMA 1373), Bay of Naples, 1893. 2 spec. (ZMUC), Bay of Muggia, 1883. 1 spec. (ZMUC), Naples, Stazione Zoologica, 1882. 9 spec. (RBCM 006-008-001), Bay of Salerno, 40°29'N, 14°46'E, VIII-2002. 3 spec. (ANSP 1880), Bay of Naples. 9 spec. (RBCM 006-008-001), Bay of Salerno, 40°29'N, 14°46'E, VIII-2002. 4 spec. (IRFA-STE 015), Rijika, Oct. 1981. Portugal. 10 spec. (SMNH 50689), Lisboa, Tajo, 9-36 m, 1869.

Description

Neotype (RBCM 005-140-001) with anterior region often swollen, bulbous compared to the remaining segments, with a constriction at septum between segments seven and eight. Body usually smooth, white, leathery, sometimes covered by minute cuticular papillae, especially behind seventh segment and near shield on dorsal side; posterior region slightly darker. Body papillae small, evenly spaced. Body up to 35 mm long, 18 mm wide, about 30 segments.
Prostomium hemispherical, without eyespots, opalescent, translucent (Fig. 13A). Peristomium rounded, flattening at the position of the mouth, devoid of papillae. Mouth circular, completely covered with minute papillae, extends from prostomium to edge of second segment.
First three chaetigers with over 10 bronze, widely separated, slightly falcate hooks, each with subdistal dark area (Fig. 13B), more evident in smaller specimens. Larger specimens with paler subdistal areas. Genital papillae protrude ventrally from body wall between segments 7 and 8. Pre-shield region with 7 segments, sometimes bearing a bundle of small, short, fine capillary chaetae laterally.
Ventro-caudal shield flat (Fig. 13C), ribbed, with concentric lines; suture restricted to anterior region. Anterior margins truncate, straight; anterior depression deep; anterior keels not exposed. Lateral margins straight, not expanded medially. Fan smooth, markedly projected beyond posterior corners, with margin smooth, barely crenulated (Fig. 13C, D).
Marginal shield chaetal fascicles include 10 lateral ones, chaetae in an oval arrangement, and six posterior fascicles, chaetae in a slightly curved arrangement. Chaetae of lateral fascicles hirsute, especially longer ones. Peg chaetae about as long as chaetae of first lateral chaetal fascicle and stout basally where chaetae emerge from cuticle, giving them a robust spine-like appearance. Additional chaetae delicate, in a small group.
Branchiae abundant; interbranchial papillae long, filamentous (Fig. 13E). Branchial plates diverging as half-fusiform areas (Fig. 13F).

Variation

The ventro-caudal shield (Fig. 13G–H) has a fan with a median notch and its lateral parts extend beyond the posterior corners level, and this is a consistent pattern seen in all specimens regardless of size. The pigmentation is deep orange in smaller specimens (Fig. 13G) and becomes reddish in larger ones (Fig. 13H, I).

Neotype locality

Izmar Bay, Aegean Sea, Turkey.

Remarks

Sternaspis scutata (Ranzani, 1817) has been widely recorded and appears to be the most common species of Sternaspis. This is the oldest named species and researchers have suggested that Sternaspis scutata is a senior synonym of at least some of the other species of the family (Ushakov 1955; Hartman 1959^[6]), others have suggested that it is in fact the only species in the family (Pettibone 1954^[7]). These ideas are so widespread that over half of the worms loaned for this study were labelled as Sternaspis scutata. However, the species has not been redefined and in order to clarify the current confusion, a neotype is proposed, described and its diagnostic features are illustrated (ICZN 1999^[8], Art. 75.3.1–75.3.3). Abbot Camilo Ranzani did not deposit the materials he described because it was not a current practice during those times (ICZN, Art. 75.3.4). However, Ranzani’s figure 13 clearly indicates that the ventro-caudal shield had a median, posterior notch, which is consistent with the proposed neotype (ICZN 1999^[8], Art. 75.3.5), and distinct from the other Mediterranean species, Sternaspis thalassemoides Otto, 1821, because it has a rather straight posterior margin. This feature is consistent and has been found in the studied materials; they included specimens from the eastern Italian coast, which would be similar to the original type locality (Adriatic Sea). However, the best specimen was selected as neotype and it was collected in the Aegean Sea, some distance from the original type locality (ICZN 1999^[8], Art. 75.3.6). As stated above, there were no differences among the materials studied. The neotype and additional paraneotypes have been deposited in the Royal British Columbia Museum (ICZN 1999^[8], Art. 95.3.7).
As stated above, Sternaspis scutata differs from Sternaspis thalassemoides by shield features, especially regarding their fan development; in Sternaspis scutata it is notched and markedly expanded beyond the level of the posterior corners, whereas in Sternaspis thalassemoides it is truncate, entire, and not expanded beyond the posterior corners level. Further, Sternaspis scutata is unique in the genus by a combination of features of their shields: the anterior margins are truncate, the lateral margins are straight or barely rounded, and the posterior margin and fan are markedly expanded beyond the posterolateral corners.

Distribution

Mediterranean Sea to the English Channel, 9–36 m depth. Deeper water records from the Eastern Mediterranean (Ben-Eliahu and Fiege 1995^[9]) deserve a careful comparison to define if they are conspecific with the shallow water material. Some records from non-Mediterranean or Northeastern Atlantic localities might belong to other, probably undescribed species. Thus the following records need to be checked: Arctic and Subarctic waters (Wesenberg-Lund 1950a^[10]: 104–105, 1950b^[11]: 46, 1951^[12]: 98, 1953^[13]: 88), Northwestern Pacific (Ushakov 1955: 353–354, fig. 131; Levenstein 1961^[14]: 167, 1966^[15]: 59, Buzhinskaja 1985^[16]: 166; Imajima 2005^[17]: 91), or Northeastern Pacific Ocean (Hartman 1971^[18]: 1422), Western Pacific (Gallardo 1968^[19]: 114), Red Sea (Fauvel 1957^[20]: 218), Indian Ocean (Wesenberg-Lund 1949^[21]: 345–346; Fauvel 1932^[22]: 213, 1953^[23]: 401–402, fig. 210a–g; Hartman 1976a^[24]: 199, 1976b^[25]: 627), Western Central (Gilbert 1984^[26]: 45.3–45.4, fig. 45.2a–f; Ibarzabal 1986: 14), Eastern Central (Fauvel 1936^[27]: 88), southeastern Atlantic (Day 1967^[28]: 648, fig. 31.1a–d), from New Zealand (Augener 1926^[29]: 283–286, fig. 22), and from the Antarctic Ocean (Hartman 1966^[30]: 55, Pl. 18, fig. 1; Hartman 1967^[31]: 141; Hartmann-Schröder 1986^[32]: 85; Hartmann-Schröder and Rosenfeldt 1989^[33]: 76, 1991^[34]: 77; Gambi and Mariani 1999^[35]: 238).

Taxon Treatment

• Sendall, K; Salazar-Vallejo, S; 2013: Revision of Sternaspis Otto, 1821 (Polychaeta, Sternaspidae) ZooKeys, 286: 1-74. doi

Other References

1. ↑ Claparède E (1869) Les Annélides Chétopodes du Golfe de Naples. Seconde Partie. Mémoires de la Société de Physique et d’Histoire Naturelle de Genève 20 (1): 1-225.
2. ↑ Rietsch M (1882) Étude sur le Sternaspis scutata. Thèse, juin 1882, École Supérieure de Pharmacie de Paris, 84 pp. [publication year based upon the documents; also published in Annals des Sciences Naturelles Paris, Zoologie, série 5 13: 1–84]
3. ↑ Fauvel P (1927) Polychètes sédentaires et addenda aus errantes, archiannelides, myzostomaires. Faune de France 16: 1-494.
4. ↑ Fauvel P (1934) Annélides polychètes de Rovigno d´Istria. Thalassia, Istituto Italo-Germanico di Biologia Marina di Rovigno d’Istria 1 (7): 1-78.
5. ↑ Townsend M, Worsfold T, Smith P, Martina L, McNeill C, Kendall M (2006) Occurrence of Sternaspis scutata (Polychaeta: Sternaspidae) in the English Channel. Cahiers de Biologie Marine 47: 281-285.
6. ↑ Hartman O (1959) Catalogue of the polychaetous annelids of the world. Part II. Allan Hancock Foundation Publications Occasional Paper 28: 355-628.
7. ↑ Pettibone M (1954) Marine polychaete worms from Point Barrow, Alaska, with additional records from the Atlantic and North Pacific. Proceedings of the United States National Museum 103: 203-356. doi: 10.5479/si.00963801.103-3324.203
8. ↑ ^{8.0 8.1 8.2 8.3} ICZN ( (1999) International Code of Zoological Nomenclature, 4th ed. International Trust for Zoological Nomenclature (The Natural History Museum), London, 306 pp. [http://www.iczn.org/iczn/index.jsp]
9. ↑ Ben-Eliahu M, Fiege D (1995) Polychaeta from the continental shelf and slope of Israel collected by the ‘Meteor’5 Exedition (1987). Senckenbergiana maritima 25: 85-105.
10. ↑ Wesenberg-Lund E (1950a) Polychaeta. Danish Ingolf-Expedition 4 (14): 1-92.
11. ↑ Wesenberg-Lund E (1950b) The Polychaeta of West Greenland with special reference to the Fauna of Nordre Strømfjord, Kvane-, and Bredefjord. Meddelelser om Grønland udgivne af Kommissionen for Videnskabelige undersøgelser I Grønland 151 (2): 1-171.
12. ↑ Wesenberg-Lund E (1951) Polychaeta. The Zoology of Iceland 2 (19): 1-182.
13. ↑ Wesenberg-Lund E (1953) The Zoology of East Greenland: Polychaeta. Meddelelser om Grønland udgivne af Kommissionen for Videnskabelige undersøgelser I Grønland 122 (3): 1-169.
14. ↑ Levenstein R (1961) Mnogotschetinkovie Chervi (Polychaeta) glubokobodnoi chaste Beringova Morya. Trudy Instituta Okeanologii, Akademiya Nauk SSSR 46: 147-178.
15. ↑ Levenstein R (1966) Mnogotschetinkovie Chervi (Polychaeta) zapadnoi chaste Beringova Morya. Trudy Instituta Okeanologii, Akademiya Nauk SSSR 81: 3-131.
16. ↑ Buzhinskaja G (1985) Mnogoschetinkovye chervil (Polychaeta) shel’fa Yuznogo Sakhalina i ikh ékologiya. Issledovaniya Fauny Morei 30 (38): 72-224.
17. ↑ Imajima M (2005) Deep-sea benthic polychaetous annelids from around Nansei Islands. National Science Museum Monographs, Tokyo 29: 37-99.
18. ↑ Hartman O (1971) Abyssal polychaetous annelids from the Mozambique basin off Southeast Africa, with a compendium of abyssal polychaetous annelids from world-wide areas. Journal of the Fisheries Research Board of Canada 28: 1407–1428. doi; 10.1139/f71-219
19. ↑ Gallardo V (1967)) Polychaeta from the Bay of Nha Trang, South Viet Nam. Scientific Results of Marine Investigations of the South China Sea and the Gulf of Thailand, 1959–1961. Scripps Institution of Oceanography NAGA Report 4: 35-279.
20. ↑ Fauvel P (1957) Contribution a la faune des annélides polychètes des côtes d’Israel, 2. Bulletin of the Research Council of Israel 6B: 213–219.
21. ↑ Wesenberg-Lund E (1949) Polychaetes of the Iranian Gulf. Danish Scientific Investigation in Iran, Part IV, 247–400.
22. ↑ Fauvel P (1932) Annelida Polychaeta of the Indian Museum, Calcutta. Memoirs of the Indian Museum, Calcutta 12: 1-262.
23. ↑ Fauvel P (1953) The Fauna of India including Pakistan, Ceylon, Burma and Malaya. Annelida Polychaeta. Indian Press, Allahabad, 12 + 507.
24. ↑ Hartman O (1974)) Polychaetous annelids of the Indian Ocean including an account of species collected by members of the International Indian Ocean Expeditions, 1963–64 and a catalogue and bibliography of the species from India. Journal of the Marine Biological Association of India 16: 191-252.
25. ↑ Ibarzábal D (1986) Lista de especies de poliquetos bentónicos cubanos. Reporte de Investigación del Instituto de Oceanología, Academia de Ciencias de Cuba 45: 1-17.
26. ↑ Gilbert K (1984) Family Sternaspidae Carus 1863. In: Uebelacker JM, Johnson PG (Eds) Taxonomic Guide to the Polychaetes ofthe Northern Gulf of Mexico. In: Mobile, Alabama, Barry A. Vittor & Associates Inc. volume 6, 45.1–45.4.
27. ↑ Fauvel P (1936) Contribution a la faune des annélides polychètes du Maroc. Mémoires de la Société des Sciences Naturelles du Maroc 43: 1-144.
28. ↑ Day J (1967) A monograph on the Polychaeta of Southern Africa. Trustees of the British Museum (Natural History), London.
29. ↑ Augener H (1926) Papers from Dr. Th. Mortensen’s Pacific Expedition 1914–16, 24. Polychaeta 3. Polychaeten von Neuseeland, 2. Sedentaria. Videnskabelige Meddelelser fra Dansk naturhistorisk Forening I København 81: 157-194.
30. ↑ Hartman O (1966) Polychaeta Myzostomidae and Sedentaria of Antarctica. Antarctic Research Series 7: 1-158. doi: 10.1029/AR007
31. ↑ Hartman O (1967) Polychaetous annelids collected by the USNS Eltanin and Staten Islands Cruises, chiefly from Antarctic seas. Allan Hancock Monographs in Marine Biology 2: 1–387.
32. ↑ Hartmann-Schröder G (1986) Die Polychaeten der 56. Reise der “Meteor” zu den South Shetland-Inseln (Antarktis). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut 83: 71-100.
33. ↑ Hartmann-Schröder G, Rosenfeldt P (1989) Die Polychaeten der “Polarsten”-Reise ANT III/2 in die Antarktis 1984. Teil 2: Cirratulidae bis Serpulidae. Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut 86: 65-106.
34. ↑ Hartmann-Schröder G, Rosenfeldt P (1991) Die Polychaeten der “Walther Herwig”-Reise 68/1 nach Elephant Island (Antarktis) 1985. Teil 2: Acrocirridae bis Sabellidae. Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut 88: 73-96.
35. ↑ Gambi M, Mariani S (1999) Polychaetes of the soft bottoms of the Straits of Magellan collected during the Italian oceanographic cruise in February-March 1991. Scientia Marina 63(Suplemento 1): 233–242.

Images

Figure 13. Sternaspis scutata (Ranzani, 1817), neotype (RBCM 005-140-001) A Anterior end, ventral view B Same, chaetae of first three chaetigers C Same, ventro-caudal shield D Paraneotype, ventro-caudal shield, oblique lateral view showing chaetal bundles E Neotype, posterior region, dorsal view F Another paraneotype, branchiae removed to show branchial plates G–I Non-type specimens (IRFA-STE 015), ventro-caudal shields. Bars: A 1.9 mm B 1.7 mm C, D, F 0.7 mm E, I 1.3 mm G 0.5 mm H 1.1 mm.