Montiel et al ., 2004 : 62
Rozbaczylo et al ., 2006a : 85
Rozbaczylo et al ., 2006b : 98
Sternaspis chilensis
S. maior Chamberlin, 1919
S. maior
S. chilensis
S. maior
S. chilensis
S. maior
S. chilensis
S. maureri
S. magellanica
sendalli
S. monroi
S. chilensis
S . chilensis
S. maureri
sendalli
S. monroi
Sternaspis scutata
Sternaspis chilensis n. sp., a new species from austral Chilean channels and fjords (Annelida, Sternaspidae)
Díaz-Díaz, Oscar
Rozbaczylo, Nicolás
Zootaxa
2017
4254
2
269
276
52F4M
[151,388,151,177]
Polychaeta
Sternaspidae
Sternaspis
Animalia
Terebellida
2
271
Annelida
species
chilensis
sp. nov.
Sternaspis scutata: Montiel et al., 2004: 62; 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. 2A); 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). Additonalmaterial. Onehundred fifty-three specimens: CIMAR7 Fiordoscruise: Moraleda Channel, St-6 ( 43°59,19´S, 73°21,87´W, 179 m), 2 specimens( SSUC7223); fjord AysénSt-21 ( 45°24,69´S, 72°51,64´W, 156 m), 2 specimens( SSUC7224); Costa Channel, St-22 ( 45°29,56´S, 73°31,03´W, 304 m), 2 specimens( SSUC7225); Estero Elefantes, St-24 ( 45°51,50’S, 73°35,41’W, 110 m), 1 specimen( SSUC7226); Estero Elefantes, St-25 ( 46°05,01´S, 73°37,82´W, 56 m), 1 specimen( SSUC7227); Jacaf Channel, St-32 ( 44°17,76´S, 73°10,78´W, 444 m), 1 specimen( SSUC7228); seno VentisqueroSt-37 ( 44°31,85´S, 72°40,09´W, 258 m), 19 specimens( SSUC7229); Puyuhuapi Channel, St-41 ( 44°53,69´S, 73°02,60´W, 238 m), 1 specimen( SSUC7230); CIMAR8 Fiordoscruise: Bocadel Guafo, St-1 ( 43°45,29´S, 74°36,78´W, 240 m), 1 specimen( SSUC7231); 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( SSUC7232). CIMAR13 Fiordoscruise: Estero Quitralco, St-31 ( 45°41’S 73°16’W, 263 m), 5 specimen( SSUC7549); 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( SSUC7550); SW Churrecue Island, St-45 ( 45°21’S, 73°39’W, 120 m), 7 specimens( SSUC7551); Costa ChannelSt-46 ( 45°31’S, 73°32’W, 300 m), 2 specimens( SSUC7552); Estero ElefantesSt-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( SSUC7553); fjord AysénSt-79 ( 45°21’S, 73°05’W, 324 m), 51 specimens( SSUC7554); fjord AysénSt-80 ( 45°25’S, 73°01’W, 200 m), 2 specimens( SSUC7555); fjord AysénSt-81 ( 45°26’S, 72°53’W, 150 m), 1 specimen( SSUC7556); PuyuhuapiChannelSt-87 ( 44°39’S, 72°44’W, 260 m), 2 specimens( SSUC7557). CIMAR17: Estero Reloncaví, St-7C ( 41°32’54”W, 72°19’48”W, 199 m), 2 specimens( SSUC7791); Gulf of Ancud, St-20 ( 42°20’06”S, 72°56’00”W, 249 m), 1 specimen( SSUC7792); Gulf of Ancud, St-14 ( 41°59’24”W, 73°00’00”W, 257 m), 1 specimen( SSUC7793). CIMAR18 Fiordoscruise: Peligroso Island, St-34 ( 43°47,8’S, 73°37,7’W, 192 m), 1 specimen( SSUC7794); Pasodel MedioSt-76 ( 45°22,9’S, 73°31,9’W, 315 m), 1 specimen( SSUC7795). 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. 2A); ten paratypes(MNNCH-ANN 15025–15034), mm long, 15 mmwide ( 10 specimens). Prostomium hemispherical, opalescent, translucent, eyespots absent ( Fig. 2B). Peristomium oval, extended as a wide band over the prostomium, with filiform papillae. Mouth oval, surface densely covered with thick filiform papillae ( Fig. 2C), extending from the base of prostomium to anterior edge of second segment. Integument of segments 1–6 densely covered by cuticular filiform papillae ( Fig. 2A´), 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. 2D, right genital papilla). First three chaetigers with 15–19 light bronze, widely separated, slightly falcate introvert hooks per bundle ( Fig. 2E). 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. 2F), 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. 2G), pubescence less obvious basally; pubescence fragile, brittle sheath covering chaetal axis ( Fig. 2H). 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. 2I). Branchiae abundant; interbranchial papillae long, filamentous ( Fig. 3A). FIGURE 1.Geographical location of the study area showing collecting stations. FIGURE 2. Holotype (MNHNCL ANN-15024) paratypes 22 mm long (MNHNCL ANN-15029)ventral view (inset: A´close-up of body papillae from region indicated by arrow), B) anterior end, ventral view; C) close-up of mouth area showing papillae; D) close-up of genital papillae; E) chaetiger 1, left side, bronze chaetae; F) posterior region showing shield, chaetae and branchial region; G) left lateral marginal shield chaetae, showing distribution pattern; H) detail of chaetae from lateral shield; I) branchial plate detail, branchiae removed, paratype. Variation.Specimens smaller than 15 mmin length with 12–15 bronze chaetae on first three chaetigers and the colour of the shield red ( Fig. 3B, F); specimens with 28–35 mmlong, have blue shields ( Figs. 3C–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 piotrowskiaeSalazar-Vallejo, 2014(from the Philippines) and Sternaspis maior Chamberlin, 1919(from Gulf of California). Sternaspis thalassemoides, S. thorsoniand S. piotrowskiaehave shields with posterior corners distinct, such that S. chilensis n. sp.Furthermore, S. chilensis n. sp.differs to S. thorsonimainly that the posterior margin in the new species is smooth to crenulate whereas it is denticulate in S. thorsoni.
Sternaspis chilensis n. sp.is very similar to S. maior Chamberlin, 1919, both have similar shields, but their main difference would be the development of the shield anterior depression, being deeper in S. maiorand shallower in S. chilensis, another differences are peristomium round, without papillae in S. maiorand with filiform papillae in S. chilensis, and marginal shield chaetal fascicles in oval pattern in S. maiorand an inverted C-shaped pattern in S. chilensis. Two Spernaspisspecies have been recorded in South America with S. maurerifrom Peru, and S. magellanicafrom the Magellanic biogeographical Province. Two other species have been recorded for relatively nearby areas, in Southern Ocean, S, sendalliand S. monroi( Fig. 4). With the description of S. chilensis 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 n. sp.is different from S. maureriand S, sendallibecause both species have the ventro-caudal shield fan with a distinct median notch; and S. monroihave the shield with ribs; concentric lines indistinct. Sternaspis scutatarecorded 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.
Typelocality.,Moraleda Channel, Southern Chile( 45°06'S, 73°38'W), 250 mdepth Southern Chile( 45°21’S, 73°05’W), 324 mdepth.
Etymology.The species name is derived from the name of the country Chileand 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 mdepth.
1455889632
CIMAR, SSUC
Additonal
179
-43.9865
Fiordos
11
-73.3645
One
2
271
CIMAR 7, SSUC 7223
2
1455889649
SSUC
156
-45.4115
Aysen
11
-72.860664
2
271
SSUC 7224
2
Aysen
1455889643
[472,1432,535,560]
SSUC
304
-45.49267
Costa Channel
11
-73.517166
2
271
SSUC 7225
2
Aysen
1455889646
[151,1151,572,597]
SSUC
110
-45.858334
Estero Elefantes
11
-73.590164
2
271
SSUC 7226
1
Aysen
1455889642
SSUC
56
-46.0835
Estero Elefantes
11
-73.63033
2
271
SSUC 7227
1
Aysen
1455889650
SSUC
444
-44.296
Jacaf Channel
11
-73.179665
2
271
SSUC 7228
1
Aysen
1455889631
SSUC
258
-44.530834
Ventisquero
11
-72.66817
2
271
SSUC 7229
19
Aysen
1455889645
[232,1217,679,704]
SSUC
238
-44.894833
Puyuhuapi Channel
11
-73.043335
2
271
SSUC 7230
1
Aysen
1455889652
CIMAR, SSUC
Fiordos
240
-43.754833
Guafo
11
-74.613
Boca
2
271
CIMAR 8, SSUC 7231
1
Aysen
1455889648
SSUC
380
-44.6895
Moraleda Channel
11
-73.50166
Moraleda Channel
2
271
SSUC 7232
5
Aysen
1455889653
CIMAR, SSUC
263
-45.683334
Estero Quitralco
1128
-73.26667
Fiordos
2
271
CIMAR 13, SSUC 7549
5
Aysen
1455889647
SSUC
192
-45.1
Moraleda Channel
1132
-73.63333
Moraleda Channel
2
271
SSUC 7550
7
Aysen
1455889639
SSUC
Iceland
120
-45.35
Island
1131
-73.65
2
271
SSUC 7551
7
1455889640
[528,1432,895,920]
SSUC
Iceland
300
-45.516666
Costa Channel
1129
-73.53333
2
271
SSUC 7552
2
1455889635
SSUC
Iceland
66
-45.383335
Costa Channel
1131
-73.5
Estero Elefantes
2
271
SSUC 7553
12
1455889633
[489,1367,967,992]
SSUC
Iceland
324
-45.35
Aysen
1131
-73.083336
2
271
SSUC 7554
51
Aysen
1455889637
SSUC
Iceland
200
-45.416668
Aysen
1130
-73.01667
2
271
SSUC 7555
2
Aysen
1455889651
SSUC
Iceland
150
-45.433334
Aysen
1130
-72.88333
2
271
SSUC 7556
1
Aysen
1455889654
[505,1432,1039,1064]
SSUC
Iceland
260
-44.65
Puyuhuapi
1135
-72.73333
2
271
SSUC 7557
2
Aysen
1455889636
[151,1334,1076,1101]
CIMAR, SSUC
Iceland
199
Estero Reloncavi
-72.33
2
271
CIMAR 17, SSUC 7791
2
Aysen
1455889634
SSUC
Iceland
249
-42.335
Gulf of Ancud
19
-72.933334
2
271
SSUC 7792
1
Aysen
1455889641
SSUC
Iceland
257
Gulf of Ancud
-73.0
2
271
SSUC 7793
1
Aysen
1455889644
CIMAR, SSUC
Iceland
192
-43.796665
Fiordos
113
-73.628334
2
271
CIMAR 18, SSUC 7794
1
1455889638
SSUC
Iceland
315
-45.381668
Medio
113
-73.53167
Paso
2
271
SSUC 7795
1