Sternaspis chilensis, Díaz-Díaz, Oscar & Rozbaczylo, Nicolás, 2017
publication ID |
https://doi.org/ 10.11646/zootaxa.4254.2.7 |
publication LSID |
lsid:zoobank.org:pub:67F6AACE-3649-4ED7-9A7C-617D5A0A98B4 |
DOI |
https://doi.org/10.5281/zenodo.6003794 |
persistent identifier |
https://treatment.plazi.org/id/03AF2433-FF06-FFBB-FF4F-BBE3DDE4A65B |
treatment provided by |
Plazi |
scientific name |
Sternaspis chilensis |
status |
sp. nov. |
Sternaspis chilensis View in CoL n. sp.
( Figures 2 View FIGURE 2 A–I, 3A–B; 4)
Sternaspis scutata: Montiel et al., 2004: 62 View in CoL ; Rozbaczylo et al., 2006a: 85 –86, figs. 5 l–o; Rozbaczylo et al., 2006b: 98 (non Ranzani, 1817).
Type material. Chile, Magellan Province, Moraleda Channel: Holotype (MNNCH-ANN 15024) 28.5 mm long, 12.0 mm wide, with 23 segments ( Fig. 2 View FIGURE 2 A); ten paratypes (MNNCH-ANN 15025–15034), 15.5–35.0 mm long, 10– 15.0 mm wide (45°06’S, 73°38’W, 250 m).
Additonal material. One hundred fifty-three specimens: CIMAR 7 View Materials Fiordos cruise: Moraleda Channel , St-6 (43°59,19´S, 73°21,87´W, 179 m), 2 specimens ( SSUC 7223 About SSUC ) GoogleMaps ; fjord Aysén St-21 (45°24,69´S, 72°51,64´W, 156 m), 2 specimens ( SSUC 7224 About SSUC ) GoogleMaps ; Costa Channel , St-22 (45°29,56´S, 73°31,03´W, 304 m), 2 specimens ( SSUC 7225 About SSUC ) GoogleMaps ; Estero Elefantes , St-24 (45°51,50’S, 73°35,41’W, 110 m), 1 specimen ( SSUC 7226 About SSUC ) GoogleMaps ; Estero Elefantes , St-25 (46°05,01´S, 73°37,82´W, 56 m), 1 specimen ( SSUC 7227 About SSUC ) GoogleMaps ; Jacaf Channel , St-32 (44°17,76´S, 73°10,78´W, 444 m), 1 specimen ( SSUC 7228 About SSUC ) GoogleMaps ; seno Ventisquero St-37 (44°31,85´S, 72°40,09´W, 258 m), 19 specimens ( SSUC 7229 About SSUC ) GoogleMaps ; Puyuhuapi Channel , St-41 (44°53,69´S, 73°02,60´W, 238 m), 1 specimen ( SSUC 7230 About SSUC ) GoogleMaps ; CIMAR 8 View Materials Fiordos cruise: Boca del Guafo , St-1 (43°45,29´S, 74°36,78´W, 240 m), 1 specimen ( SSUC 7231 About SSUC ) GoogleMaps ; Moraleda Channel, St-8 (44°26,11´S, 73°27,54´W, 380 m), 2 specimens; Moraleda Channel , St-9 (44°41,37´S, 73°30,10´W, 322 m), 3 specimens ( SSUC 7232 About SSUC ) GoogleMaps . CIMAR 13 View Materials Fiordos cruise: Estero Quitralco , St-31 (45°41’S 73°16’W, 263 m), 5 specimen ( SSUC 7549 About SSUC ) GoogleMaps ; Moraleda Channel, St-40 (44°49´S, 73°30’W, 192 m), 1 specimen; Moraleda Channel , St- 41 (45°06’S, 73°38’W, 250 m), 6 specimens ( SSUC 7550 About SSUC ) GoogleMaps ; SW Churrecue Island, St-45 (45°21’S, 73°39’W, 120 m), 7 specimens ( SSUC 7551 About SSUC ) GoogleMaps ; Costa Channel St-46 (45°31’S, 73°32’W, 300 m), 2 specimens ( SSUC 7552 About SSUC ) GoogleMaps ; Estero Elefantes St-50 (46°12’S, 73°40’W, 66 m), 1 specimen; Costa Channel , St-76 (45°23’S, 73°30’W, 297 m), 11 specimens ( SSUC 7553 About SSUC ) GoogleMaps ; fjord Aysén St-79 (45°21’S, 73°05’W, 324 m), 51 specimens ( SSUC 7554 About SSUC ) GoogleMaps ; fjord Aysén St-80 (45°25’S, 73°01’W, 200 m), 2 specimens ( SSUC 7555 About SSUC ) GoogleMaps ; fjord Aysén St-81 (45°26’S, 72°53’W, 150 m), 1 specimen ( SSUC 7556 About SSUC ) GoogleMaps ; Puyuhuapi ChannelSt-87 (44°39’S, 72°44’W, 260 m), 2 specimens ( SSUC 7557 About SSUC ) GoogleMaps . CIMAR 17 View Materials : Estero Reloncaví , St-7C (41°32’54”W, 72°19’48”W, 199 m), 2 specimens ( SSUC 7791 About SSUC ) ; Gulf of Ancud , St-20 (42°20’06”S, 72°56’00”W, 249 m), 1 specimen ( SSUC 7792 About SSUC ) GoogleMaps ; Gulf of Ancud , St-14 (41°59’24”W, 73°00’00”W, 257 m), 1 specimen ( SSUC 7793 About SSUC ) . CIMAR 18 View Materials Fiordos cruise: Peligroso Island, St-34 (43°47,8’S, 73°37,7’W, 192 m), 1 specimen ( SSUC 7794 About SSUC ) GoogleMaps ; Paso del Medio St-76 (45°22,9’S, 73°31,9’W, 315 m), 1 specimen ( SSUC 7795 About SSUC ) GoogleMaps . CIMAR 20: St-20 (1 specimen), St-93 (1 specimen).
Description. Holotype (MNNCH-ANN 15024) 28.5 mm long, 12.0 mm wide, with 23 segments ( Fig. 2 View FIGURE 2 A); ten paratypes (MNNCH-ANN 15025–15034), mm long, 15 mm wide (10 specimens). Prostomium hemispherical, opalescent, translucent, eyespots absent ( Fig. 2 View FIGURE 2 B). Peristomium oval, extended as a wide band over the prostomium, with filiform papillae. Mouth oval, surface densely covered with thick filiform papillae ( Fig. 2 View FIGURE 2 C), extending from the base of prostomium to anterior edge of second segment. Integument of segments 1–6 densely covered by cuticular filiform papillae ( Fig. 2 View FIGURE 2 A´), papillae less numerous on ventral surface. Genital papillae protrude ventrolaterally from intersegmental groove between segments 7 and 8. Surface of segments seven and eight with many stout cuticular papillae especially near genital papillae; some cuticular papillae with small grains of sediment adhered to bases, genital papillae with long papillae on proximal end and few rounded papillae in middle region ( Fig. 2 View FIGURE 2 D, right genital papilla).
First three chaetigers with 15–19 light bronze, widely separated, slightly falcate introvert hooks per bundle ( Fig. 2 View FIGURE 2 E). The base and subdistal falcate chaetae end with dark areas. The integument closer to falcate chaetae with dark spots.
Pre-shield region with 7 segments, without fine capillary chaetae but with abundant minute papillae, both dorsally and ventrally, and rows of clusters of short filaments closer to ventro-caudal shield, especially on dorsal surface. Many thin filiform papillae in the inferior margin of the ventro-caudal shield, with capillary chaetae protruding laterally from body wall, with long papillae surrounding the base of the bundle.
Ventro-caudal shield violaceous-gray, with radial ribs and concentric lines distinct ( Fig. 2 View FIGURE 2 F), outer margin blue. Fan continuous, with crenulated margin; median notch indistinct. Anterior margins rounded; anterior depression shallow; anterior keels not exposed. Lateral margins medially expanded, reduced posteriorly.
Marginal shield chaetal fascicles include: 11 lateral ones, with 10–14 hirsute capillary chaetae arranged with an inverted C- shaped pattern ( Fig. 2 View FIGURE 2 G), pubescence less obvious basally; pubescence fragile, brittle sheath covering chaetal axis ( Fig. 2 View FIGURE 2 H). Posterior most fascicle, in the corner of the shield, with long, delicate capillaries between peg chaetae and first bundle of posterior chaetae; posterior shield margin with six fascicles, with 8–10 chaetae arranged in lineal pattern. Peg chaetae short, with a broad base in cross section, emerge from cuticle on a slightly raised mound. Two subtriangular branchial plates diverging ( Fig. 2 View FIGURE 2 I). Branchiae abundant; interbranchial papillae long, filamentous ( Fig. 3 View FIGURE 3 A).
Variation. Specimens smaller than 15 mm in length with 12–15 bronze chaetae on first three chaetigers and the colour of the shield red ( Fig. 3 View FIGURE 3 B, F); specimens with 28–35 mm long, have blue shields ( Figs. 3 View FIGURE 3 C–E). Three specimens with anterior keels partially exposed. The number of bronze chaetae of the introvert increases with the size of the specimens. In some specimens the posterior chaetal bundles are covered by a hyaline structure, which seems to encapsulate each bundle.
Remarks. Sternaspis chilensis n. sp. is included in the group of sternaspids having shields with ribs and concentric lines, fan continuous, without a distinct median notch and with margin crenulated. The group includes: Sternaspis rietschi Caullery, 1944 (from Indonesia), Sternaspis thalassemoides Otto, 1821 (from Northeastern Atlantic Ocean and Mediterranean Sea), Sternaspis thorsoni Sendall & Salazar-Vallejo, 2013 (from Indian), Sternaspis piotrowskiae Salazar-Vallejo, 2014 (from the Philippines) and Sternaspis maior Chamberlin, 1919 (from Gulf of California). Sternaspis thalassemoides , S. thorsoni and S. piotrowskiae have shields with posterior corners distinct, such that S. chilensis n. sp. Furthermore, S. chilensis n. sp. differs to S. thorsoni mainly that the posterior margin in the new species is smooth to crenulate whereas it is denticulate in S. thorsoni .
Sternaspis chilensis View in CoL n. sp. is very similar to S. maior Chamberlin, 1919 View in CoL , both have similar shields, but their main difference would be the development of the shield anterior depression, being deeper in S. maior View in CoL and shallower in S. chilensis View in CoL , another differences are peristomium round, without papillae in S. maior View in CoL and with filiform papillae in S. chilensis View in CoL , and marginal shield chaetal fascicles in oval pattern in S. maior View in CoL and an inverted C- shaped pattern in S. chilensis View in CoL .
Two Spernaspis species have been recorded in South America with S. maureri View in CoL from Peru, and S. magellanica from the Magellanic biogeographical Province. Two other species have been recorded for relatively nearby areas, in Southern Ocean, S, sendalli View in CoL and S. monroi View in CoL ( Fig. 4 View FIGURE 4 ). With the description of S. chilensis View in CoL n. sp., the knowledge and richness of polychaetes in the South Eastern Pacific Ocean off Chile, in the Magellanic biogeographical Province and for the family is increased. Compared with the other species recorded in the region, S. chilensis View in CoL n. sp. is different from S. maureri View in CoL and S, sendalli View in CoL because both species have the ventro-caudal shield fan with a distinct median notch; and S. monroi View in CoL have the s hield with ribs; concentric lines indistinct. Sternaspis scutata View in CoL recorded by Gambi & Mariani (1999) and Bremec et al. (2000) cannot be confirmed, but they might belong to the same species we are describing in this contribution.
Type locality.,Moraleda Channel, Southern Chile (45°06'S, 73°38'W), 250 m depth Southern Chile (45°21’S, 73°05’W), 324 m depth.
Etymology. The species name is derived from the name of the country Chile and the suffix indicates it lives in this region.
Distribution. Austral Chilean channel and fjord region from Estero Reloncaví (41°32’54”W, 72°19’48”W) to Strait of Magellan (53°34’S, 70°04’W), between 50 and 515 m depth.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
Kingdom |
|
Phylum |
|
Class |
|
Order |
|
Family |
|
Genus |
Sternaspis chilensis
Díaz-Díaz, Oscar & Rozbaczylo, Nicolás 2017 |
Sternaspis scutata: Montiel et al., 2004 : 62
Rozbaczylo 2006: 85 |
Rozbaczylo 2006: 98 |
Montiel 2004: 62 |