Daylithos parmatus ( Grube, 1877 ) Salazar-Vallejo, 2012

Salazar-Vallejo, Sergio I., 2012, 3562, Zootaxa 3562, pp. 1-62 : 44-48

Daylithos parmatus ( Grube, 1877) n. comb., restricted

Figures 17, 18

Stylarioides parmata Grube 1877:71 ; Wiktor 1980:277.

Stylarioides parmatus: Grube 1878 : v (materials), 199–201, Pl. 11, Fig. 1a–d; Fauvel 1935:340–341; Fauvel 1939:348–349. Pherusa parmata : Palpal-latoc 1981:37.

Type material. Tropical Western Pacific, Philippine Islands. Lectotype ( MNHW-391 ) and paralectotype ( MNHW-391 a), Bohol (09º50' N, 124º10' E), 37–64 m, July 1863 ( Grube 1878: v indicates more specimens; not available, probably lost).

Additional material: Tropical Western Pacific. Philippine Islands. One specimen ( LACM-AHF- 4868), Bohol Island (09º50' N, 124º10' E), 0.5–2.0 m, Sep. 2003, J. Hinterkircher, coll. (27 mm long, 2 mm wide, cephalic cage made by chaetigers 1–2, chaetae 8.5 mm long, 96 chaetigers; papillae per anterior row in chaetiger 10: club-shaped, 17; dorsal shield over chaetigers 1–4 (no ventral shield); chaetiger 7 with aristate multiarticulate capillaries (no pseudocompound hook); first simple hooks from chaetiger 8; hooks in chaetiger 10, 25, 50, 70: 2, 3, 2, 5)). One specimen ( SMF- 5138), Emerald, Mindanao Island (08º00' N, 125º00' E), Philippines, Stat. 56 (no further data), V. Storch, coll. (23.5 mm long, 3.5 mm wide, cephalic cage made by chaetigers 1–2, chaetae 9 mm long, 96 chaetigers; papillae per anterior row in chaetiger 10:14 club-shaped; dorsal shield (previously removed) over chaetigers 1–4 (no ventral shield); chaetiger 7 without chaetae (previously broken), probably aristate multiarticulate capillaries (no pseudocompound hook on chaetiger 5); first falcate hooks from chaetiger 8 (missing, thick basis); hooks in chaetiger 10, 25, 50, 70: 2, 3, 2, 5). Hainan, China. One specimen ( SMF- 15388), anterior fragment, German Expedition to Hainan Island, Shalao, 6 m, 4 Apr. 1992, D. Fiege & R. Sun, coll. (2.8 mm wide, cephalic cage 9 mm long, chaetiger 1 with 8 notochaetae; first falcate neurohooks from chaetiger 8). Seven specimens ( SMF- 15389), three complete, German Expedition to Hainan Island, Lingchang, 10 Apr. 1992, D. Fiege & R. Sun, coll. (complete specimens 20–35 mm long, 2.5 mm wide, cephalic cage 8.0– 8.5 mm long, 70–87 chaetigers; chaetiger 1 with 7–8 notochaetae per bundle; first falcate neurohooks from chaetiger 7(smallest)–8; anterior fragments 2.5–4.0 mm wide, cephalic cage 8–10 mm long, chaetiger 1 with 8–9 notochaetae; first falcate neurohooks from chaetiger 8–9 (largest)). Six specimens ( SMF- 15390), two complete, four anterior and one median fragments, German Expedition to Hainan Island, Lingchang, 11 Apr. 1992, D. Fiege & R. Sun, coll. (complete specimens 16–25 mm long, 2 mm wide, cephalic cage 6–9 mm long, 68–74 chaetigers; chaetiger 1 with 6–7 notochaetae per bundle; first falcate neurohooks from chaetiger 7; anterior fragments 2.0– 3.5 mm wide, cephalic cage 7.5–10.0 mm long, chaetiger 1 with 6–7 notochaetae; first falcate neurohooks from chaetiger 7–9 (largest)). Two specimens ( SMF- 15391), mature male complete and anterior end of mature female, German Expedition to Hainan Island, Meixia, 9 Apr. 1992, D. Fiege & R. Sun, coll. (male 26 mm long, 4 mm wide, cephalic cage 9 mm long, 91 chaetigers; chaetiger 1 with 9 notochaetae per bundle; first falcate neurohooks from chaetiger 8; female anterior fragment 2 mm wide, cephalic cage 11 mm long, chaetiger 1 with broken notochaetae; first falcate neurohooks from chaetiger 8; oocytes about 125 µm in diameter). One specimen ( SMF- 15392), mature female, without posterior end, German Expedition to Hainan Island, Lingchang, 10 Apr. 1992, D. Fiege & R. Sun, coll. (14 mm long, 1.5 mm wide, cephalic cage 5 mm long, 38 chaetigers; first neurohooks in chaetiger 7; larger oocytes about 125 µm). Four specimens ( SMF- 15393), three complete and one anterior fragment, German Expedition to Hainan Island, Lingchang, 7 Apr. 1992, D. Fiege & R. Sun, coll. (complete 22–43 mm long, 2.5–4.0 mm wide, cephalic cage 6.5–10.0 mm long, 70–88 chaetigers; chaetiger 1 with 7–9 notochaetae per bundle; first falcate neurohooks from chaetiger 7–9). Two specimens ( SMF- 15395), one complete, Senckenberg Museum Hainan Expedition, Xincun, Tauchang, Stat. 92P, 26 Mar. 1992, D. Fiege & R. Sun, coll. (complete 23 mm long, 2 mm wide, cephalic cage 8 mm long, 91 chaetigers; chaetiger 1 with 7 notochaetae per bundle; first falcate neurohooks from chaetiger 8). Four specimens ( SMF- 15400), two complete, Senckenberg Museum Hainan Expedition, Xincun, Stat. 92P, 2 m, 27 Mar. 1992, D. Fiege & R. Sun, coll. (complete ones 16–23.5 mm long, 2–3.5 mm wide, cephalic cage 5.0– 8.5 mm long, 60–75 chaetigers; chaetiger 1 with 7 notochaetae per bundle; first falcate neurohooks from chaetiger 6–8). Vietnam. One specimen ( MNHN- 427), Van-Ro (22º03' N, 106º32' E), Annam (no further data), very swollen anteriorly. One specimen ( MNHN- 507) Nha trang, C. Dawydoff, coll. (no further data; partly dried-out. No ventral shield. No pseudocompound hooks. Flat posterior region). Gulf of Thailand. Four specimens ( CAS- 168304), including an anterior end, off Ko-Sichang (13º10' N, 100º49' E), 4 May 1968, F.B. Steiner, coll. (better specimens 29/ 44 mm long, 2.5/ 3 mm wide, cephalic cage made by chaetigers 1–2, chaetae 8/ 9 mm long, 85/87 chaetigers; papillae per anterior row in chaetiger 10: 12, rounded, small; dorsal shield over chaetigers 1–5; chaetiger 7 with aristate multiarticulate capillaries; first hooks from chaetiger 8; hooks in chaetiger 10, 30, 50, 60: 2/2, 2/2, 3/2, 4/3; one mature female with ova about 100 µm). Coral portion with tubes ( CAS- 168305), off Ko-Sichang, 4 May 1968, F.B. Steiner, coll. Two specimens ( MNHN- 427), one complete, Rearee, Cambodia, shore, C. Dawydoff, coll. (no further data); one with anterior end exposed (used for anterior end descr.); no ventral shield nor pseudocompound hooks, falcate hooks from chaetiger 8, posterior region depressed (complete 25 mm long, 3.8 mm long, cephalic cage 7.5 mm long, 85 chaetigers). Malaysia. One specimen ( MCZ- 55666), off Singapore (01.3º N, 103.8º E), 1909–1910, Bryant & Palmer, coll. (body partly dehydrated, with most chaetae smothered, and without dorsal shield and because of the smooth surface, it may also have had a ventral shield; 18 mm long, 2.7 mm wide, cephalic cage made by chaetigers 1–2, chaetae 10 mm long, ca. 65 chaetigers; papillae per anterior row in chaetiger 10, globose, medium sized, most eroded; dorsal shield over chaetigers 1–5(?); chaetiger 7 with broken chaetae, thinner than hooks but tips missing; first hooks from chaetiger 8; hooks in chaetiger 10, 30, 50: 4, 3, 2). Australia, Northern Territory. One specimen ( NTM- 17875), Stat. NTDIOB (12°28.35' S, 130°50.57' E), Iron Ore Wharf, Darwin Harbor,, Aug. 1998 – Mar. 1999, no depth data, CSIRO CRIMP Survey Team, coll. (27 mm long, 3 mm wide, cephalic cage 10.5 mm long, 93 chaetigers; first hooks from chaetiger 8; posterior end cylindrical; hooks in chaetigers 10, 30, 50, 60: 1, 2, 2, 3). One specimen ( NTM- 17884), Stat. NTDNBO (12°27.75' S, 130°49.40' E), Naval Base, Darwin Harbor,, 18 Aug. 1998, no depth data, CSIRO CRIMP Survey Team, coll. (32.5 mm long, 2 mm wide, cephalic cage 9 mm long, 82 chaetigers; first hooks from chaetiger 9; posterior end flat; hooks in chaetigers 10, 30, 50, 60: 2, 3, 3, 4).

Description. Lectotype (MNHW-391), mature female, pale, damaged, most cephalic cage chaetae lost, some parapodia removed, broken in two pieces ( Fig. 17A). Body cylindrical, tapering posteriorly, distal region flat; 18.5 mm long, 2 mm wide, cephalic cage 6 mm long, 90 chaetigers. Tunic thin, without sediment particles; body papillae short, rounded, in two irregular rows per segment, dorsal papillae mostly eroded, ventrally less damaged, difficult to be counted.

Anterior end modifications observed by dissection of non-type material (SMF-15389); cephalic hood short, margin smooth. Prostomium low cone with black eyes, anterior ones larger; caruncle well developed, two longitudinal ciliary bands running from the anterior end of prostomium, continued to branchial plate margin. Palps thick; palp keels reduced. Dorsal lip well-developed; lateral lips wide, well-developed; ventral lip reduced to a small lappet ( Fig. 18B).

Branchiae cirriform, about as long as palps, in two different widths, separated in two lateral groups, each with filaments arranged in 4–5 concentric rows, inner three rows with thicker filaments, marginal and distal rows with thinner filaments, about 35–45 filaments per group ( Fig. 18B). Nephridial lobes in branchial plate not seen.

Cephalic cage chaetae about 1/3 as long as body length, or three times longer than body width ( Fig. 17C). Chaetigers 1–3 involved in the cephalic cage, chaetae of chaetiger 3 smaller, but about twice as long as following ones. Cephalic cage chaetae arranged in short ventrolateral rows; about 4 chaetae left per fascicle, others broken (SMF-5138) with 6 noto- and neurochaetae in chaetiger 1, chaetiger 2 with 4 noto- and 6 neurochaetae.

Anterior dorsal margin of first chaetiger with a median lobe projected anteriorly, distally eroded. Anterior chaetigers without especially long papillae. Chaetigers 1–3 of about the same length. Sand cemented anterior shield dorsal, reaching chaetiger 4, posterior margin abruptly cut ( Fig. 17B–D). Chaetal transition from cephalic cage to body chaetae abrupt; falcate neurohooks start in chaetiger 8; no pseudocompound hooks. Gonopodial lobes not seen (larger specimens with shallow, transverse pits in chaetiger 5, slightly ahead of neurochaetae).

Parapodia poorly developed, chaetae emerge from body wall. Parapodia lateral; median neuropodia ventrolateral. Notopodia detectable by chaetal fascicles; neuropodia short rounded lobes; both in posterior region with longer papillae. Noto- and neuropodia distant to each other.

Median notochaetae broken in lectotype specimens (SMF specimens very thin multiarticulate capillaries, as long as 1/8 body width, 2–3 per fascicle, articles short basally, longer medial- and distally). Neurochaetae multiarticulate capillaries in chaetigers 1–7, in chaetigers 4–7 abruptly tapering, aristate. Falcate neurohooks from chaetiger 8, their abundance per chaetiger: 10:2, 30:2, 50:3 ( Figs 17E, 18F), 70:4 ( Figs 17G, 18G); anterior and median region with hooks in transverse rows; posterior region with neurohooks arranged in ∪–patterns. Anterior hooks slightly bent, subdistally expanded, far posterior hooks straight, acute, with a lateral keel ( Fig. 18G).

Posterior end depressed, subdistally swollen ( Figs 17A, 18A), tapering to a blunt tip; terminal anus, without anal cirri.

Paralectotype MNHW-391a: Complete (481 on small label), partly dehydrated, damaged ( Fig. 17C); most notochaetae lost. Body dark, cylindrical, tapering posteriorly, posterior region flat; 33 mm long (half body swollen, posterior half thin, flat), 2.5 mm wide (average), cephalic cage 7 mm long, 81 chaetigers. Tunic thin, without sediment. Falcate simple hooks from chaetiger 8; falcate hooks per chaetiger 10:2 ( Fig. 17E), 30:2, 50:2, 70:5 ( Fig. 17G). Neurohooks arranged in most chaetigers in transverse rows; posterior region with hooks in transverse rows in larger syntype (other specimens with them arranged in a ∪-pattern).

Remarks. Daylithos parmatus ( Grube, 1877) n. comb. was briefly described. The free translation would be: Neck plate over the first 4 chaetigers, neurochaetae of anterior 8 chaetigers only capillaries. All bristles of the 2 first segments strongly, splendidly shining and iridescent, as long as the length of chaetigers 10–26 (30). Papillae very isolated and flat ( Grube 1877:71). The following year, Grube published a more complete description and provided some illustrations ( Grube 1878). His material coming from three different depths: 37–64 m (Pandanon), or 18 m (Laping and Bohol), and probably contain more than one species. The type material contains more than one species; herein, a lectotype and a paralectotype are being designated to restrict the species definition.

Almost all flabelligerids with dorsal shields were identified with this species name based upon specimens from the Western tropical Pacific. It was employed instead of introducing other names to polychaete species lists for several different regions in the world. Indeed, S. parmatus was described from the Philippine Islands, and S. iris Michaelsen, 1892 , was described from Sri Lanka. These two species were regarded as synonyms by Willey (1905:289–290), and followed by Fauvel (1919:434–435, 1932:179–180, 1953:346–347), who revised materials from nearby the type locality. This was even followed by authors working on materials from farther localities like New Zealand ( Ehlers, 1907:21–22, Augener 1926:180–181, 1927:354), India ( Soota et al. 1981), or even from the Atlantic Ocean ( Augener 1933:199). This extended distribution does not correspond to the same species as will be shown below, and could be explained by an incomplete knowledge of morphological features for these two species. They bore into calcareous substrates such as corals ( Fig. 18H, inserts), and have been found also among serpulid tubes. In fact, the early record by Stimpson (1856:391) of his Siphonostomum laeve as boring in corals was apparently overlooked (see above).

However, following the features herein newly illustrated, D. parmatus and D. iris ( Michaelsen, 1892) n. comb. are different species. In D. parmatus median and posterior chaetigers have neurohooks flanged, tapered, whereas in D. iris they are subdistally expanded, not tapered nor flanged.

Further, these two species have been shown to differ after the original and later records. Grube (1878, Pl. 11, Fig. 1a) showed that specimens belonging to S. parmatus have a dorsal shield with a longitudinal furrow; further, Palpal-latoc (1981:37) indicated that it has neurohooks from chaetigers 6 or 7. In contrast, the dorsal shield in S. iris is entire, as illustrated by Fauvel (1953:346, Fig. 179b), and there were two transversal series of papillae per segment ( Fauvel 1932:180). From examination of material from the Indian Ocean, it seems that neurohooks start in a more posterior region. The variation in chaetal numbers in the cephalic cage may be size dependent; however, the start and number of neurohooks is almost constant (see above under S. inflata ). Grube’s largest specimen was 29 mm long, and Palpal-latoc found them to reach 40 mm in length. Thus, the difference in the dorsal shield being as entire ( D. iris ) or longitudinally cleft ( D. parmatus ), could be used to separate these species.

These two species also differ in the relative width of branchiae because in D. iris larger branchiae are twice as wide as thinner ones, whereas in D. parmatus the larger branchiae are four times as wide as the thinner ones.

Distribution. The above materials are all from the Tropical Western Pacific Ocean. The records for other localities like the ones by Rodríguez-Gómez (1988:417), Willey (1905:289–290, Pl. 8, Fig. 5), Fauvel (1932:179–180), Okuda (1937 b:299, Fig. 43), Fauvel (1953:346–347, Fig. 179b), Imajima & Hartman (1964:303), and Hartmann-Schröder (1979:138) might belong to other species. Wehe & Fiege (2002:50) indicated that the type locality was fixed by Hartman (1959), but it was included in the original listing by Grube himself ( Grube 1877:67).