Scyphoproctus profundus, Silva & Amaral, 2019

Silva, Camila Fernanda Da & Amaral, Antonia Cecilia Zacagnini, 2019, Scyphoproctus Gravier, 1904 (Annelida, Capitellidae): description of three new species and relocation of Heteromastides Augener, 1914 in Scyphoproctus, Zootaxa 4560 (1), pp. 95-120 : 108-113

Scyphoproctus profundus sp. nov.

( Figures 8 ̄10)

Type series. Holotype ( ZUEC POL 20596): state of Rio de Janeiro, Campos Basin—Paraíba do Sul River (22°1'9''S, 40°31'55''W): coll. 24 Jul 2009; sublittoral; 49m deep; Stn. HAB 17/FOZ 23; 1 spec . Paratypes: state of Espírito Santo, Espírito Santo Basin (18°40'55,3''S, 38°55'41,48"W): paratypes 1̄5 ( ZUEC POL 20530): coll. 19 Dec 2010; sublittoral; 29m deep; Stn. AMB 1/FOZ 7; 5 specs . Paratypes 6 and 7 ( ZUEC POL 20740): coll. 0 2 Feb 2012; sublittoral; 34m deep; Stn. AMB 7/E2; 2 specs . Paratypes 8̄10 ( ZUEC POL 20741): coll. 17 Jul 2013; sublittoral; 147m deep; Stn. AMB 14/A4; 3 specs. State of Rio de Janeiro, Campos Basin (22°52'1''S, 40°57'28''W): paratypes 11 and 12 ( ZUEC POL 20540): coll. 0 3 Jul 2009; sublittoral; 90m deep; Stn. HAB 16/C04; 2 specs . Paratypes 13̄16 ( ZUEC POL 20544): coll. 23 Feb 2009; sublittoral; 103m deep; Stn. HAB 11/E04; 4 specs . Paratypes 17̄22 ( ZUEC POL 20551): coll. 0 5 Jul 2009; sublittoral; 99m deep; Stn. HAB 16/F04; 6 specs . Paratypes 23 and 24 ( ZUEC POL 20556): coll. 22 Feb 2009; sublittoral; 78m deep; Stn. HAB 11/C03; 2 specs . Paratypes 25 and 26 ( ZUEC POL 20566): coll. 16 Jul 2009; sublittoral; 53m deep; Stn. HAB 17/B02; 2 specs . Paratypes 27 and 28 ( ZUEC POL 20594): coll. 19 Jul 2009; sublittoral; 18m deep; Stn. HAB 17/FOZ 5; 2 specs . Paratype 29 ( ZUEC POL 20595): coll. 23 Jul 2009; sublittoral; 20m deep; Stn. HAB 17/FOZ 2; 1 spec .

Additional material examined. State of Rio de Janeiro—Exclusive Economic Zone. (ZUEC POL 6771): (23°20'S, 41°22'W); coll. 28 Feb 1998; sublittoral; 110m deep; Stn. 6759; 1 spec. (ZUEC POL 6772): (23°20'S, 41°22'W); coll. 28 Feb 1998; sublittoral; 110m deep; Stn. 6759; 1 spec. (ZUEC POL 6887): (23°26'S, 41°15'W); coll. 28 Feb 1998; sublittoral; 145m deep; Stn. 6762; 1 spec. (ZUEC POL 6895): (23°08'S, 41°00'W); coll. 0 1 Mar 1998; sublittoral; 100m deep; Stn. 6763; 1 spec. (ZUEC POL 6883): (23°20'S, 41°22'W); coll. 28 Feb 1998; sublittoral; 110m deep; Stn. 6759; 2 specs. State of São Paulo—Exclusive Economic Zone. (ZUEC POL 6739): (25°11'S, 47°08'W); coll. 16 Feb 1997; sublittoral; 157m deep; Stn. 6658; 5 specs. (ZUEC POL 6746): (24°07'S, 44°42'W); coll. 11 Jan 1998; sublittoral; 101m deep; Stn. 6669; 1 spec. State of São Paulo, São Sebastião, Araçá Bay (23°48'S, 45°24'W). (ZUEC POL 20523): coll. 24 Nov 2011; soft-bottom; intertidal; Stn. 7(3); 4 specs. (ZUEC POL 20524): coll. 26 Sep 2011; soft-bottom; intertidal; Stn. 4(2)A; 8 specs. (ZUEC POL 20526): coll. 0 5 Feb 2011; soft-bottom; intertidal; Stn. 37(2)A; 1 spec. (ZUEC POL 20527): coll. 0 5 Feb 2011; intertidal; Stn. 39(2)A; 20 specs. (ZUEC POL 20529): coll. 0 5 Feb 2011; soft-bottom; intertidal; Stn. 38(1)A; 11 specs. (ZUEC POL 20531): coll. 29 Oct 2011; soft-bottom; intertidal; Stn. 20(2)A; 1 spec. State of São Paulo, São Sebastião, São Francisco Beach (23°44'54"S, 45°24'34"W). (ZUEC POL 20539): coll. 23 Jun 2013; sandy beach; intertidal; Stn. 45; 2 specs. State of Rio de Janeiro, Campos Basin—continental shelf. (ZUEC POL 20541): (22°52'1''S, 40°57'28''W); coll. 22 Feb 2009; sublittoral; 92m deep; Stn. HAB 11/C04; 1 spec. (ZUEC POL 20542): (21°42'37''S, 40°8'59''W); coll. 0 7 Jul 2009; sublittoral; 147m deep; Stn. HAB 16/H05; 6 specs. (ZUEC POL 20543): (21°23'2''S, 40°15'9''W); coll. 0 6 Mar 2009; sublittoral; 147m deep; Stn. HAB 13/I05; 5 specs. (ZUEC POL 20545): (23°12'8''S, 40°59'35''W); coll. 0 2 Jul 2009; sublittoral; 142m deep; Stn. HAB 16/B05; 1 spec. (ZUEC POL 20546): (21°23'37''S, 40°15'38''W); coll. 21 Jul 2009; sublittoral; 88m deep; Stn. HAB 17/I03; 2 specs. (ZUEC POL 20547): (22°17'42''S, 40°26'59''W); coll. 0 4 Jul 2009; sublittoral; 103m deep; Stn. HAB 16/ E04; 5 specs. (ZUEC POL 20548): (21°9'10''S, 40°16'7''W); coll. 0 7 Mar 2009; sublittoral; 101m deep; Stn. HAB 13/I04; 1 spec. (ZUEC POL 20549): (22°3'45''S, 40°9'59''W); coll. 25 Feb 2009; sublittoral; 75m deep; Stn. HAB 11/G03; 2 specs. (ZUEC POL 20550): (21°9'9''S, 40°16'7''W); coll. 21 Jul 2009; sublittoral; 10 m deep; Stn. HAB 17/I04; 8 specs. (ZUEC POL 20552): (22°12'37''S, 40°13'18''W); coll. 24 Feb 2009; sublittoral; 99m deep; Stn. HAB 11/F04; 7 specs. (ZUEC POL 20553): (21°43'10''S, 40°11'30''W); coll. 0 8 Jul 2009; sublittoral; 72m deep; Stn. HAB 16/H03; 3 specs. (ZUEC POL 20554): (21°42'53''S, 40°10'16''W); coll. 0 9 Mar 2009; sublittoral; 98m deep; Stn. HAB 13/H04; 1 spec. (ZUEC POL 20555): (22°19'31''S, 40°37'19''W); coll. 23 Feb 2009; sublittoral; 73m deep; Stn. HAB 11/D03; 17 specs. (ZUEC POL 20557): (23°10'5''S, 41°3'6''W); coll. 0 2 Jul 2009; sublittoral; 107m deep; Stn. HAB 16/B04; 2 specs. (ZUEC POL 20558): (22°7'43''S, 40°18'46''W); coll. 24 Feb 2009; sublittoral; 73m deep; Stn. HAB 11/F03; 1 spec. (ZUEC POL 20559): (22°12'53''S, 40°51'12''W); coll. 26 Feb 2009; sublittoral; 52m deep; Stn. HAB 11/D02; 1 spec. (ZUEC POL 20560): (21°42'37''S, 40°8'59''W); coll. 0 9 Mar 2009; sublittoral; 147m deep; Stn. HAB 13/H05; 2 specs. (ZUEC POL 20561): (21°22'59''S, 40°19'41''W); coll. 0 5 Mar 2009; sublittoral; 52m deep; Stn. HAB 13/I02; 2 specs. (ZUEC POL 20562): (22°37'35''S, 41°21'51''W); coll. 27 Feb 2009; sublittoral; 53m deep; Stn. HAB 11/B02; 1 spec. (ZUEC POL 20563): (22°19'31''S, 40°37'19''W); coll. 0 4 Jul 2009; sublittoral; 73m deep; Stn. HAB 16/D03; 12 specs. (ZUEC POL 20564): (21°42'53''S, 40°10'15''W); coll. 0 7 Jul 2009; sublittoral; 98m deep; Stn. HAB 16/H04; 1 spec. (ZUEC POL 20565): (21°22'58''S, 40°19'41''W); coll. 21 Jul 2009; sublittoral; 53m deep; Stn. HAB 17/I02; 1 spec. (ZUEC POL 20567): (22°59'47''S, 41°21'7''W); coll. 21 Feb 2009; sublittoral; 77m deep; Stn. HAB 11/B03; 1 spec. (ZUEC POL 20568): (22°57'28''S, 40°50'30''W); coll. 0 3 Jul 2009; sublittoral; 143m deep; Stn. HAB 16/C05; 1 spec. (ZUEC POL 20569): (22°3'45''S, 40°9'58''W); coll. 0 6 Jul 2009; sublittoral; 75m deep; Stn. HAB 16/G03; 1 spec. State of Rio de Janeiro, Campos Basin—Paraíba do Sul River. (ZUEC POL 20592): (22°12'31''S, 40°14'8''W); coll. 24 Jul 2009; sublittoral; 97m deep; Stn. HAB 17/FOZ 43; 3 specs. (ZUEC POL 20593): (22°1'10''S, 40°31'53''W); coll. 12 Mar 2009; sublittoral; 49m deep; Stn. HAB 13/FOZ 23; 2 specs. (ZUEC POL 20597): (21°17'31''S, 40°48'21''W); coll. 0 8 Mar 2009; sublittoral; 24m deep; Stn. HAB 13/FOZ 14; 1 spec. (ZUEC POL 20598): (22°1'9''S, 40°31'55''W); coll. 24 Jul 2009; sublittoral; 49m deep; Stn. HAB 17/FOZ 23; 2 specs. (ZUEC POL 20599): (21°45'13''S, 40°14'7''W); coll. 24 Jul 2009; sublittoral; 67m deep; Stn. HAB 17/FOZ 41; 5 specs. State of Espírito Santo, Espírito Santo Basin (18°40'55,3''S, 38°55'41,48"W). (ZUEC POL 20525): coll. 19 Dec 2010; sublittoral; 29m deep; Stn. AMB 1/FOZ 7; 4 specs. (ZUEC POL 20528): coll. 18 Jul 2011; sublittoral; 46m deep; Stn. AMB 2/FOZ 11 2 specs. (ZUEC POL 20532): coll. 18 Jul 2011; sublittoral; 28m deep; Stn. AMB 2/FOZ 7; 11 specs. (ZUEC POL 20533): coll. 18 Jul 2011; sublittoral; 49m deep; Stn. AMB 2/FOZ 16; 6 specs. (ZUEC POL 20534): coll. 18 Jul 2011; sublittoral; 46m deep; Stn. AMB 2/FOZ 18; 1 spec. (ZUEC POL 20535): coll. 19 Dec 2010; sublittoral; 46m deep; Stn. AMB 1/FOZ 17; 1 spec. (ZUEC POL 20742): coll. 17 Jul 2013; sublittoral; 28m deep; Stn. AMB 13/G02; 3 specs. (ZUEC POL 20743): coll. 0 2 Feb 2012; sublittoral; 45m deep; Stn. AMB 7/ B03; 10 specs. (ZUEC POL 20744): coll. 0 2 Feb 2012; sublittoral; 134m deep; Stn. AMB 7/E04; 9 specs. (ZUEC POL 20745): coll. 0 2 Feb 2012; sublittoral; 121m deep; Stn. AMB 6/D04; 2 specs. (ZUEC POL 20746): coll. 0 2 Dec 2011; sublittoral; 43m deep; Stn. AMB 7/F03; 9 specs. (ZUEC POL 20747): coll. 0 2 Dec 2011; sublittoral; 35m deep; Stn. AMB 7/C02; 10 specs. (ZUEC POL 20748): coll. 17 Jul 2013; sublittoral; 156m deep; Stn. AMB 14/B04; 1 spec. (ZUEC POL 20749): coll. 0 2 Feb 2012; sublittoral; 121m deep; Stn. AMB 7/F04; 2 specs. (ZUEC POL 20750): coll. 17 Jul 2013; sublittoral; 163m deep; Stn. AMB 12/CAND 04; 2 specs. (ZUEC POL 20751): coll. 0 2 Feb 2012; sublittoral; 36m deep; Stn. AMB 7/A02; 3 specs. State of Paraíba, Cabo Branco Beach (7°08'S, 34°47'W). (ZUEC POL 20536): coll. 0 1 Feb 2010; in rhodoliths; intertidal; 1 spec. (ZUEC POL 20538): coll. 0 8 Feb 2009; in rhodoliths; intertidal; 1 spec. State of Paraíba, Jacumã Beach (7°14'S, 34°47'W). (ZUEC POL 20537): coll. 29 Jan 2010; in rhodoliths; intertidal; 1 spec.

Description. Complete holotype 20 mm long, 0.8 mm wide for 60 chaetigers. Complete specimens ranged from 2.5– 22 mm long, 0.2–0.8 mm wide for 15–60 chaetigers; incomplete specimens ranged from 0.2–1.5 mm wide. Body rounded in cross-section; thorax almost same width as abdomen ( Figs 8A ; 9A ̄B; 10A); abdomen same width toward pygidium. Whitish color in alcohol.

Prostomium robust, wider than long basally, rounded anteriorly ( Figs 8A ; 9A, H ); nuchal organs not observed; eyespots as a pair of oblique pigmented areas ( Fig. 9A ). Proboscis globular-shaped, finely papillated. Peristomium longer than following thoracic segments ( Figs 8A ; 9A ̄B). Incomplete inter-segmental groove between peristomium and achaetous segment ( Figs 8A ; 9A, H ).

Thorax with 15 segments, including the peristomium, one additional achaetous segment, and 13 chaetigers. Bilimbate capillaries in noto- and neuropodia of chaetigers 1–13; last chaetiger with hooded hooks on one side of segment. Thorax smooth; chaetigers strongly biannulate and rectangular ( Figs 8A ; 9A ; 10A ); moderate depth of inter-segmental grooves between chaetigers. First chaetiger biramous. Noto- and neuropodial lobes well separated; notopodia inserted dorsally and neuropodia ventrally. Lateral organs present from the achaetous segment, more conspicuous on larger specimens. Transition between thorax and abdomen subtle, marked mainly by chaetal change ( Figs 8A ; 10A ).

Abdominal chaetigers without capillaries. Abdominal notopodia and neuropodia with poorly developed tori pads; first 1–3 chaetigers (size dependent) with notopodial lobes almost joined dorsally ( Fig. 8 A–B), following chaetigers with lobes well separated throughout abdomen ( Figs 8C ; 9C ); neuropodial lobes separated, with nearly same distance throughout the abdomen ( Figs 8 B–C; 9D). First abdominal notopodia with 18 hooks per fascicle, decreasing in number toward posterior end; first abdominal neuropodia with 12 hooks per fascicle, maintaining the number of hooks to middle of abdomen. Anterior notopodial hooks (with SEM) with long and rounded main fang, right angle with shaft, surmounted by approximately 16 teeth arranged in four rows (3–4–5–4); thick hood with smooth margin, “U”-shaped aperture ( Fig. 10B ). Posterior notopodial hooks (with SEM) with long and pointed main fang, right angle with shaft, surmounted by more than 30 teeth arranged in six rows (intercalated pattern among teeth of tori); thin hood with smooth margin, “V”-shaped aperture (narrow at the top and broad basally) ( Fig. 10E ). Anterior neuropodial hooks (first two abdominal chaetigers) (with SEM) with long and pointed main fang, right angle with shaft, surmounted by approximately 20 teeth arranged in four rows; thick hood with smooth margin, “U”-shaped aperture ( Fig. 10F ). Posterior neuropodial hooks (from third abdominal chaetiger) (with SEM) with large and robust main fang, right angle with shaft, surmounted by approximately 40 teeth arranged in six rows; large thin hood with robust fringed margin, “U”-shaped aperture ( Fig. 10G ).

Seven pre-pygidial segments with neuropodial hooks and notopodial spines; 3,3,4,5,5,6,6 spines per notopodial lobe, greater number toward plaque; dorsal edges of pre-pygidial segment rounded. Anal plaque welldeveloped formed by three fused chaetigers; square-shaped, with flat and elevated borders; plaque with sets of acicular spines in horizontal rows protruding midway on each side, not reaching plaque margin (5,5,3 each side). Small anus near inferior margin, on base of membrane; two median and thin cirri (two-thirds of plaque length), 9x longer than wide; median membrane triangular, posterior border (where cirri emerge) 1.2x wider than anterior margin (near anus) ( Figs 8D ; 9F ̄G; 10C̄D).

Variation. Paratypes with 12–15 segments, including the peristomium, one additional achaetous segment, and 10–13 chaetigers. Adult specimens with bilimbate capillaries in noto- and neuropodia of chaetigers 1–10/13. Number of hooks of the first abdominal lobe size dependent, notopodium ranging from 3 to 42 hooks and neuropodium from 3 to 36 hooks.

Methyl green staining pattern. Prostomium staining darkly ( Fig. 9H ). Dorsal region of peristomium, achaetous segment and chaetiger 1 with a large continuous dark patch ( Fig. 9H ). Thoracic chaetigers staining uniformly green ( Fig. 9B ). In the abdominal region, first 2–3 chaetigers staining entirely; the next few chaetigers staining dorsally with a dark band around the tori pads; afterwards staining is restricted to parapodial tori, but more intense on notopodia ( Fig. 9B, E, I ). Small dark speckles stained around abdominal lateral organs ( Fig. 9E ).

Remarks. Scyphoproctus profundus sp. nov. belongs to a group of species with set of acicular spines in horizontal rows protruding midway on each side of the plaque, not reaching the plaque margin, which includes S. aciculatus , S. pseudoarmatus , S. pullielloides , S. somalus , S. steinitzii and S. towraiensis .

Scyphoproctus aciculatus , S. pullielloides , S. somalus and S. steinitzii differ from Scyphoproctus profundus sp. nov. by the number of pre-pygidial segments, which is three in S. aciculatus , S. pullielloides and S. steinitzii ; two in S. somalus ; and five in Scyphoproctus profundus sp. nov. Scyphoproctus aciculatus and S. steinitzii are also different from this new species by the absence of a median membrane separating the cirri and number of rows of spines on the plaque. There are two to three spine rows in Scyphoproctus profundus sp. nov., two in S. aciculatus , and four in S. steinitzii .

Scyphoproctus profundus sp. nov. and S. towraiensis have five pre-pygidial segments, however S. towraiensis has up to 13 acicular spines on each side of pre-pygidial segments whereas S. profundus sp. nov. has up to seven; additionally, dorsal edges of pre-pygidial segments in S. towraiensis are triangular with a pointed tip, and dorsal edges of pre-pygidial segments in S. profundus sp. nov. are rounded.

Both species are also similar in having four types of hooded hooks along the abdomen; besides the equal number of types of hooded hooks, they vary between both species in type and position on noto- and neuropodia.

Etymology. Latin word that means “deep”. This species was named after its depth of occurrence, since it is the one recorded in greater depth among the 17 described species.

Habitat. From intertidal to sublittoral regions (0–163m); in soft-bottom and rhodoliths.

Type locality. Rio de Janeiro, Brazil, 22°1'9''S, 40°31'55''W ( South Atlantic Ocean ) .

Distribution. South Atlantic Ocean: Brazil (states of Espírito Santo, Paraíba, Rio de Janeiro and São Paulo).

Figures

FIGURE 8. Scyphoproctus profundus sp. nov. (A) Anterior end, lateral view; (B) Anterior abdominal chaetiger; (C) Posterior abdominal chaetiger; (D) Anal plaque, dorsal view. Scale bars: A, 1 mm; B, C, D, 0.2 mm.

FIGURE 9. Scyphoproctus profundus sp. nov. (A) Anterior end, dorso-lateral view; (B) Thoracic region, dorso-lateral view, methyl green staining pattern; (C) Abdominal region; dorsal view; (D) Abdominal region; ventral view; (E) Thoracic and abdominal region; lateral view, methyl green staining pattern; (F) Anal plaque, frontal view; (G) Anal plaque, lateral view; (H) Anterior end, dorso-lateral view, methyl green staining pattern; (I) Abdominal region, ventral view, methyl green staining pattern. Scale bars: A, D, H, I, 0.5 mm; B, 1 mm; C, E, F, 0.2 mm; G, 0.1 mm.

FIGURE 10. Scyphoproctus profundus sp. nov., SEM. (A) Anterior end, dorso-lateral view; (B) Anterior notopodial hooded hook, frontal view; (C) Anal plaque, lateral view; (D) Anal plaque, dorsal view; (E) Posterior notopodial hooded hooks, top view; (F) Anterior neuropodial hooded hooks, top view; (G) Posterior neuropodial hooded hooks, top view. Scale bars: A, 0.5 mm; B, 2 µm; C, D, 0.1 mm; E, F, G, 5 µm.