Ehlersileanira simplex ( Ehlers, 1887 ) Cruz-Gómez, 2022

Cruz-Gómez, Christopher, 2022, Reinstatement of Ehlersileanira simplex (Ehlers, 1887) comb. nov. reinst., distinct from E. incisa (Grube, 1877) (Annelida: Sigalionidae), with a key to all the species of Ehlersileanira, Journal of Natural History 56 (1 - 4), pp. 157-172 : 164-168

Ehlersileanira simplex ( Ehlers, 1887) comb. nov., reinst.

( Figures 1 (h–n), 2(h–n), 3(m–w), 4(k–t); Table 1 )

Sthenelais simplex Ehlers, 1887: 60–63 , pl. 13, figs 2,3, pl. 14, figs 1–5 (partim, not pl. 14, fig. 6, which belongs to an Acoetidae sensu Pettibone, 1970 )

Leanira simplex – Augener, 1906: 106–107, pl. 1, figs 16–17 (non Ehlers, 1887, Leanira sp. )

Leanira incisa – Augener, 1918: 107 (non Grube, 1877; syn.)

Ehlersileanira incisa – Pettibone, 1970: 19, lectotype designation (non Grube, 1877)

Type locality

Off Louisiana, Gulf of Mexico, 28°42’N, 88°40’W, 97 m ( Ehlers 1887) .

Material examined

Grand Caribbean: United States, UMML 22.1090 , 1 spec . (incomplete, anterior fragment), 38 segments, 2.5 cm long, 1.7 cm to segment 30, 0.4 cm wide, Florida, off Jensen Beach , R / V Gerda, Cruise 6333, Sta . 174 (27.266N, 79.933W), 30 January 1963, depth 180 m; UMML 6518–576 , 1 spec . (incomplete, anterior fragment, poor condition), 66 segments, 3.8 cm long, 1.2 cm to segment 30, 0.4 cm wide, Florida, off Cayo Hueso , R / V Gerda, Sta . 576 (24.483N, 81.666W), 13 April 1965, depth 73 m; UMML 6525–656 , 1 spec (incomplete, anterior fragment), 98 segments, 10.5 cm long, 3.2 cm to segment 30, 0.6 cm wide, Florida, off Jupiter Island , R / V Gerda, Sta . 6525 (27.116N, 79.816W), 16 July 1965, depth 240 m; UF 286 , 1 spec . (incomplete, anterior fragment, poor condition), 46 segments, 2.3 cm long, 1.5 cm to segment 30, 0.3 cm wide, Sea Horse Key (29.10N, 83.066W), 31 March 1973, J . Taylor leg ; Mexico, ECOSUR-3223, 1 spec . (incomplete, anterior fragment), 87 segments, 0.9 cm long, 0.5 cm to segment 30, 0.15 cm wide, Campeche, off Chenkán, B / O Justo Sierra, Sta. 5 (19.333N, 91.316W), 16 August 1984, E . Escobar leg .; Honduras, UMML 6802–619 , 1 spec . (incomplete, anterior fragments), 42 segments, 2.8 cm long, 1.7 to segment 30, 6 mm wide, off Punta Sal National Park , R / V Pillsbury, Sta . 6802 (15.966N, 87.566W), 20 March 1967, depth 40 m; Costa Rica, UMML 7101–1321 , 10 spec . (incomplete, anterior fragments), 46–81 segments, 3.3–12 cm long, 1.3–3.5 cm to segment 30, 0.5–0.8 cm wide, off Limón, R / V Pillsbury, Sta . 1321 (10.100N, 83.066W), 27 January 1971, depth 210 m; Colombia, UMML 6607–375 , 1 spec . (incomplete, anterior fragment); 82 segments, 8.2 cm long, 2.8 cm to segment 30, 0.9 cm wide, off Caño La Balsa , R / V Pillsbury, Sta . 375 (09.983N, 76.000W), 14 July 1966, depth 133 m; UMML 6607–398 , 1 spec . (incomplete, anterior fragment, poor condition), 47 segments, 11.5 cm long, 1.8 cm to segment 30, 0.5 cm wide, off Puerto Escondido , R / V Pillsbury, Sta . 398 (9.100N, 76.516W), 17 July 1966, depth 146 m; UMML 6806–797 , 2 spec . (incomplete, anterior fragments), 53–92 segments, 5.5– 7.2 cm long, 2.1–2.2 cm to segment 30, 0.6–0.7 cm wide, off Isla de Tierra Bomba , R / V Pillsbury, Sta . 797 (10.333N, 75.750W), 1 August 1968, depth 160 m; Guadeloupe , UMML 6806–943 , 1 spec . (incomplete, anterior fragment), 61 segments, 5.8 cm long, 2.3 cm to segment 30, 0.6 cm wide, off Port-Louis , R / V Pillsbury, Sta . 943 (16.433N, 61.600W), 17 July 1969, depth 274 m; Venezuela, UMML 6806–724 , 3 spec . (incomplete, anterior fragments), 38–57 segments, 3.5–5.3 cm long, 2.4–2.7 cm to segment 30, 0.5–0.7 cm wide, off Cumaná , R / V Pillsbury, Sta . 724 (10.766N, 64.600W), 21 July 1968, depth 442 m; UMML 6806–736 , 1 spec . (incomplete, anterior fragment), 46 segments, 4.3 cm long, 2.3 cm to segment 30, 0.6 cm wide, off Chirimena , R / V Pillsbury, Sta . 736 (11.00N, 65.916W), 22 July 1968, depth 112 m; UMML 6806–749 , 1 spec . (incomplete, anterior fragment), 37 segments, 3.3 cm long, 1.2 cm to segment 30, 0.3 cm wide, off Puerto Cabello , R / V Pillsbury, Sta . 749 (10.633N, 67.966W), 25 July 1968, depth 59 m; UMML 6806–762 , 1 spec . (incomplete, anterior fragment, very poor condition), 125 fragmented segments, 3.9 cm long, 2.4 cm to segment 30, 0.9 cm wide, Gulf of Venezuela, off Punta Cardón , R / V Pillsbury, Sta . 762 (11.600N, 70.566W), 27 July 1968, depth 34 m; UMML6806- 766 , 1 spec . (incomplete, anterior fragment), 34 segments, 1.2 cm long, 1 cm to segment 30, 0.3 cm wide, off Gulf of Venezuela , R / V Pillsbury, Sta . 766 (12.250N, 70.666W), 28 July 1968, depth 64 m; Jamaica, UMML 7006–1261 , 1 spec . (incomplete, anterior fragment), 74 segments, 10.7 cm long, 2.8 cm to segment 30, 0.9 cm wide, off Treasure Beach , R / V Pillsbury, Sta . 1261 (17.583N, 77.833W), 15 July 1970, depth 710 m.

Description

Best-preserved specimen (UMML 7101–1321). Description based on UMML 22.1090.

Incomplete specimen, anterior fragment with 38 segments, 2.5 cm long and 0.4 cm wide. Body whitish, long, depressed ( Figure 1 (h)). Specimen with all elytra lost.

Prostomium oval, wider than long, fused with tentacular segment ( Figure 1 (i, k)). Three small antennae. Median antenna on antero-dorsal prostomial margin; auricles paired, round, large, as long as median antennal ceratophore; style large with two articles of similar length ( Figure 1 (j)). Lateral antennae dorsally fused with tentacular parapodia, with well-defined ceratophores and long styles. Eyes indistinct, nuchal organs barely visible. Tentacular segment with 3–5 dorsal stylodes between base of dorsal tentacular cirri and lateral antennae. Dorsal tentacular cirri longer than neuropodia including chaetae, ventral tentacular cirri slightly shorter than dorsal ones. Facial tubercle visible in ventral view, between palps ( Figure 1 (m, n)). Palps long, reaching segment 18, with inner palpal sheath long, outher palpal sheath slightly shorter ( Figure 1 (l, n)). First three anterior parapodia directed anteriorly. Segment 2 with conical ventral buccal cirri, larger than the following. Segment 3 without dorsal cirri and dorsal tubercles.

Branchiae beginning at segment 16; ctenidial pads placed between notopodia and elytrophores, beginning at segment 9. Ventral cirri short, with short basis. Tubular segmental papilla beginning at segment 21–23, short, slightly shorter than ventral cirri.

Parapodia from segment 4 ( Figure 2 (h–l)): Notopodia short, posterior upper lobe indiscernible, anterior lower lobe well developed, anterior upper lobe with 4–5 stylodes and a larger stylode under acicular lobe. Notochaetae consist of 1–3 thick, spinous capillariessimple chaetae. Neuropodia conical with 3–6 large stylodes, posterior upper and lower lobes short, anterior upper and lower lobes barely distinguishable. Neurochaetae mostly lost, only two compound spinigers left, with canaliculated blades; simple pinnate chaetae not observed. Left elytron missing. From an additional specimen of similar size (UMML 6518–576): left anterior elytron from segment 4 smooth and rectangular ( Figure 2 (m, n)).

Parapodia from segment 21 (median segment): Notopodia large, posterior upper lobe lanceolate, anterior lower lobe well developed, anterior upper lobe conical with 3–5 stylodes, acicular lobe without longer stylodes ( Figure 3 (m–q)). Notochaetae consist of two fascicles of spinous capillariessimple chaetae, supra-acicular lobe with 11–14 chaetae, infra-acicular fascicle with 20–24 chaetae ( Figure 3 (r)). Neuropodia conical with 5–8 large stylodes, upper posterior lobe well developed, lower posterior lobe short, anterior upper and lower lobes indistinct ( Figure 3 (m–q)). Neurochaetae consist of 3–4 pinnate simple chaetae in supra-acicular position ( Figure 3 (u)), and 21–25 compound spinigers with canaliculated blades ( Figure 3 (s–t)). Left elytron missing. From an additional specimen of similar size (UMML 6518–576): left elytron of middle segment smooth, bilobed ( Figure 3 (v, w)). Pygidium unknown, all specimens lacked posterior-most segments.

Figures

Figure 1. Ehlersileanira incisa, non-type specimen (UMML 6504–259): (a) anterior first segments, dorsal view; (b) prostomium, dorsal view; (c) median antenna, close-up; (d) drawing of prostomium, dorsal view; (e) anterior first segments, ventral view; (f) facial tubercle, close-up; (g) drawing of prostomium, ventral view. Ehlersileanira simplex, non-type specimen (UMML 22.1090): (h) anterior first segments, dorsal view; (i) prostomium, dorsal view of prostomium; (j) median antenna, close-up; (k) drawing of prostomium, dorsal view; (l) anterior first segment, ventral view; (m) facial tubercle, close-up; (n) drawing of prostomium, ventral view. Scale bars: a, h = 5 mm; b, e, d, g, i, l, k and n = 2 mm; c, f, j and m = 0.5 mm. Abbreviations: au: auricles; buc: buccal cirrus; ce: ceratophore; ds: distal style; dtc: dorsal tentacular cirrus; ft: facial tubercle; ipas: inner palpal sheath; lan: lateral antenna; man: median antenna; nuo: nuchal organ; opas: outer palpal sheath; pa: palp; vtc: ventral tentacular cirrus.

Figure 2. Ehlersileanira incisa, non-type specimen (UMML 6504–259): (a) segment 4, anterior view; (b) drawing of a (chaetae omitted); (c) segment 4, posterior view; (d) drawing of c (chaetae omitted); (e) diagrammatic end view of same; (f) elyron from same; (g) diagrammatic of same. Ehlersileanira simplex, non-type specimen (UMML 22.1090): (h) segment 4, anterior view; (i) drawing of h (chaetae omitted); (j) segment 4, posterior view; (k) drawing of j (chaetae omitted); (l) diagrammatic end view of same. Non-type specimen (UMML 6518–576): (m) elytron from segment 4, anterior and posterior margins bent; (n) diagrammatic of same. Scale bars: 500 µm. Abbreviations: al: anterior lower lobe; as: anterior side; au: anterior upper lobe; pl: posterior lower lobe; ps: posterior side; pu: posterior upper lobe.

Figure 3. Ehlersileanira incisa, non-type specimen (UMML 6504–259): (a) segment 22, anterior view; (b) drawing of a (chaetae omitted); (c) segment 22, posterior view; (d) drawing of c (chaetae omitted); (e) diagrammatic end view of same; (f) notochaeta, same; (g) detail of f; (h) compound supra-acicular neurochaeta, same; (i) compound infra-acicular neurochaeta, same; (j) simple neurochaeta, same; (k) diagrammatic of elytron from median segment; (l) elytron from median segment. Ehlersileanira simplex, non-type specimen (UMML22.1090): (m) segment 21, anterior view; (n) drawing of m (chaetae omitted); (o) segment 21, posterior view; (p) drawing of o (chaetae omitted); (q) diagrammatic end view of same; (r) notochaeta, same; (s) compound supra-acicular neurochaeta, same; (t) compound infra-acicular neurochaeta, same; (u) simple neurochaeta, same. Non-type specimen (UMML 6518–576, Florida, same length as UMML 22.1090): (v) diagrammatic of elytron from median segment; (w) elytron from median segment. Scale bars: a–e, m–q, v, w = 500 µm; f = 200 µm; g–j, r–u = 100 µm; k, l = 1 mm. Abbreviations: al: anterior lower lobe; as: anterior side; au: anterior upper lobe; pl: posterior lower lobe; ps: posterior side; pu: posterior upper lobe.