Perinereis pangcahae, Hsueh, 2024

Perinereis nigropunctata ( Horst, 1889) View in CoL ( Fig. 16 View Fig , Table 4)

Nereis nigro-punctata Horst 1889: 171 View in CoL , pl. 8, figs. 1–3.

Perinereis nigro-punctata Gravier 1901: 188–191 View in CoL , text-figs. 190–193, table 2, pl. 11, fig. 49.

Perinereis marjorii View in CoL Southern 1921: 595–597, text-figs. 7 8a–c, pl. 23, fig. 10A–G.

Nereis (Perinereis) yorkensis Augener 1922: 24 View in CoL , fig. 6a–e.

Nereis (Perinereis) nigropunctata Horst 1924: 171 View in CoL .

Perinereis nigropunctata Monro 1931a: 16 View in CoL ; Fauvel 1953: 210, fig. 107b–f; Day 1967: 337, fig. 14.13r–v; Wu 1967: 64–66, fig. 9a–d; Hartmann-Schröder 1979: 116–117, figs. 203–206; Hutchings et al. 1991: 256–257, fig. 10a–e.

Examined material: 1 specimen, NMNS 8748- 93, Linshanbi (25°16.99'N, 121°30.59'E), habitat type: IRHB, 1 November 2003; 3 specimens, NMNS 8748- 94–96, Wanlitong (21°59.73'N, 120°42.26'E), habitat type: IRHB, 16 December 2007; 2 specimens, NMNS 8748-97–98, Jihuei (23°06.87'N, 121°24.21'E), habitat type: IRHB, 27–28 March, 2014; 3 specimens, NMNS 8748-99–101, Jihuei (23°06.87'N, 121°24.21'E), habitat type: IRHB, 27 September, 2014; 9 specimens, NMNS 8748-102–110, Jihuei (23°06.87'N, 121°24.21'E), habitat type: IRHB, 28–29 April, 2017; 4 specimens, NMNS 8748 - 111 – 114, Shadao (21 ° 54.78 ' N, 120°50.83'E), habitat type: IRHB, 17 October 2020.

Description: Based on 11 complete specimens ( NMNS 8748-93, NMNS 8748-95–96, NMNS 8748- 104, NMNS 8748-106–107, NMNS 8748-109, NMNS 8748-111–114; all atoke) and 11 incomplete specimens ( NMNS 8748-94, NMNS 8748-97–103, NMNS 8748- 105, NMNS 8748-108, NMNS 8748-110; all atoke): Body length 61.0 (10.5–57.0, n = 11) mm with 75 (60– 79, n = 11) chaetigers, chaetiger 10 width 2.5 (1.0–2.1, n = 11) mm, excluding parapodia; beige to dark brown in alcohol ( Fig. 16A–D View Fig ). Prostomium wider than long, lateral antennae antero-lateral, shorter than palps, palpophores globose, palpostyles spheroid. Four pairs of tentacular cirri, longest one reaching chaetiger 2 (1–7, n = 20). Two pairs of eyes, in trapezoidal arrangement. Tentacular belt about 1.3x (1.2–1.4x, n = 20) longer than chaetiger 1. Pharynx with dark brown jaws, each with 6 teeth; paragnath pattern: I = 5 (3–11, n = 20, same sample size on following areas), in triangle; II = 15 (6–23) (left), 16 (6–22) (right), in 2–3 oblique rows; III = 23 (12–30) (center region with 19 (8–25) cones, in 4 (3–4) transverse rows; 2 lateral regions, each with 2 (1–3) cones, in longitudinal line); IV = 20 (8–32) (left), 19 (9–35) (right), in 4 (4–6) oblique rows, without bars; V = 3 (1–5), in triangle (cluster, T-shaped or V-shaped); VI = 1 (1) (left), 1 (mostly 1, one case of 1+ 0–1 cone) (right), shield-shaped bars; VII –VIII = 37 (18–39), in 2–3 rows. Ridge pattern of areas VI – V – VI, λ-shaped ( Fig. 16A–D View Fig , Table 4).

Dorsal cirri digitiform throughout, medially attached to dorsal ligule on anterior to mid-body chaetigers, about as long as dorsal ligule on anterior chaetigers, about 0.5x as long as dorsal ligule, attached 2/3 to base of dorsal ligule on posterior chaetigers, about 0.4x longer than dorsal ligule ( Fig. 16E–G View Fig , Table 4).

Dorsal ligule subconical with blunt tip on anterior chaetigers, as long as median ligule, subconical on mid-body to posterior chaetigers, about 2.0x longer than median ligule, base of dorsal ligule bulged and elongated, about 3.3x longer than median ligule on posterior chaetigers; center lobe of dorsal ligule with one irregular-shaped glandular mass ( Fig. 16E–G View Fig ). Notopodial prechaetal lobe present throughout ( Fig. 16E–G View Fig , Table 4).

Median ligule conical on anterior chaetigers, about 1.4x longer than neuroacicular ligule, subconical on mid-body to posterior chaetigers, about 1.3–1.4x longer than neuroacicular ligule ( Fig. 16E–G View Fig ).

Neuroacicular ligule with predominant inferior lobe on anterior chaetigers, inferior and superior lobes subequal in length on posterior half of mid-body to posterior chaetigers, about as long as ventral ligule. Neuropodial postchaetal lobe absent. Ventral ligule subconical throughout. Ventral cirri basally attached to ventral ligule, about 0.6x as long as ventral ligule on anterior chaetigers, about as long as ventral ligule on posterior chaetigers ( Fig. 16E–G View Fig ).

Notochaetae present from chaetiger 3 to posterior chaetigers, homogomph spinigers present throughout. Supra-acicular fascicle of neuropodia: homogomph spinigers and short-bladed heterogomph falcigers with serrations present throughout. Subacicular fascicle of neuropodia: short-bladed heterogomph falcigers with serrations and heterogomph spinigers present throughout ( Fig. 16H, I View Fig , Table 4).

Pygidium with anus crenulated; anal cirri cirriform, as long as last 4 (2–6) (n = 9) chaetigers ( Table 4).

Distribution: North and West Australia, Red Sea, Indian Ocean ( India, Madagascar, Marshall Islands), Southeast Asia (Borneo, Malaysia, Singapore), Taiwan ( Hutchings et al. 1991).

Remarks: Morphology of present specimens agree with descriptions in Horst (1889), Wu (1967) and Hutchings et al. (1991). Moreover, collection locations of the present material also agree with the distribution of the species reported in Wu (1967) (see Fig. 1). Paragnath pattern on area III of the pharynx in P. nigropunctata ( Horst, 1889) shows discrepancy between different reports. Horst (1889, collection locations: Malaysia), Wu (1967, collection locations: Taiwan) and Hutchings et al. (1991, collection locations: North and West Australia) noted that this species has lateral groups of cones on area III of the pharynx, whereas other reports (i.e., Gravier (1901), collection locations: Red Sea, Southern (1921), collection locations: India; Augener (1922), collection locations: North Australia, Fauvel (1953), collection locations: India; Day (1967), collection locations: Red Sea; Hartmann-Schroder (1979), collection locations: Malaysia; Hylleberg et al. (1986), collection locations: Malaysia) stated otherwise. The reason for this discrepancy between different geographic locations of the species is unclear.

Perinereis pangcahae sp. nov. ( Fig. 17 View Fig , Table 2) urn:lsid:zoobank.org:act:B134E1BE-5E30-4AC0-ACDB-F5BCC4F680C7

Material examined: Holotype, NSNM 8748-115 , Jihuei (23°06.87'N, 121°24.21'E), habitat type: IRHB, 28 April 2017 GoogleMaps . Paratypes: 3 specimens, NSNM 8748- 116–118, Jihuei (23°06.87'N, 121°24.21'E), habitat type: IRHB, 29 April 2017; 1 specimen, NSNM 8748-119, Jihuei (23°06.87'N, 121°24.21'E), habitat type: IRHB, 27 March 2014. Non-types: 4 specimens, NSNM 8748- 120–123, Jihuei (23°06.87'N, 121°24.21'E), habitat type: IRHB, 27–28 March 2014; 3 specimens, NSNM 8748-124–126, Jihuei (23°06.87'N, 121°24.21'E), habitat type: IRHB, 28–29 April 2017.

Etymology: The name is derived from the Pangcah aboriginal tribe of eastern Taiwan, as a tribute to their glittering cultures.

Description: Based on holotype ( NSNM 8748- 115, complete specimen; atoke), paratypes ( NSNM 8748-116–119, 4 complete specimens; all atoke) and non-types (7 incomplete specimens; all atoke): holotype, atoke, body length 98.5 (73.5–111.5, n = 4) mm with 155 (136–160, n = 4) chaetigers, chaetiger 10 width 2.6 (2.7–4.5, n = 4) mm, excluding parapodia; light to dark brown in alcohol ( Fig. 17A–C View Fig ). Prostomium wider than long, lateral antennae antero-lateral, as long as (or shorter) than palps, palpophores globose, palpostyles spheroid. Four pairs of tentacular cirri, longest one reaching chaetiger 3 (2–5, n = 10). Two pairs of eyes, in trapezoidal arrangement. Tentacular belt about 1.2x (1.1–1.4x) longer than chaetiger 1. Pharynx with dark brown jaws, each with 4 (4–5, n = 11) teeth; paragnath pattern: I = 4 (2–5, n = 10), in cluster (same sample size on remaining areas); II = 13 (9–15) (left), 11 (8–14) (right), in 3 oblique rows; III = 25 (17–32) (center region with 20 (13–25) cones, in 4 (3–5) transverse rows; 2 lateral regions, each with 2 (2–5) or 3 (2–4) cones in longitudinal line); IV = 30 (20–41) (left), 31 (19–36) (right), in 4 (4–6) oblique rows, without bars; V = 3, in triangle; VI = 1 (1) (left), 1+1 cone (1) (right), chevron-shaped bars; VII –VIII = 29 (21–33), in 2–3 (2–4) rows. Ridge pattern of areas VI – V – VI, ɔc-shaped ( Fig. 17D View Fig , Table 2).

Dorsal cirri digitiform throughout, attached 1/3 to base of dorsal ligule on anterior to mid-body chaetigers, about 0.8x as long as dorsal ligule on anterior chaetigers, about 0.6x as long as dorsal ligule on mid-body chaetigers, medially attached to dorsal ligule on posterior chaetigers, about 0.3x as long as dorsal ligule ( Fig. 17E–G View Fig , Table 2).

Dorsal ligule subconical, about 2.7x longer than median ligule on anterior chaetigers, about 1.9x longer than median ligule on mid-body to posterior chaetigers; proximal lobe with one irregular-shaped glandular mass on mid-body chaetigers, center and proximal lobes with one large irregular-shaped glandular mass on posterior chaetigers ( Fig. 17E–G View Fig ). Notopodial prechaetal lobe absent ( Table 2).

Median ligule subconical throughout, about 1.4x longer than neuroacicular ligule on anterior chaetigers, about 1.7–1.8x longer than neuroacicular ligule on mid-body to posterior chaetigers ( Fig. 17E–G View Fig ).

Neuroacicular ligule with predominant inferior lobe, about 0.5x as long as ventral ligule on anterior chaetigers, inferior and superior lobes subequal in length on mid-body to posterior chaetigers, about 0.7x as long as ventral ligule. Neuropodial postchaetal lobe absent. Ventral ligule subconical throughout. Ventral cirri mid-ventrally attached to ventral edge of parapodia, about 0.6x as long as ventral ligule on anterior chaetigers, about 0.7x as long as ventral ligule on mid-body chaetigers, about 0.6x as long as ventral ligule on posterior chaetigers ( Fig. 17E–G View Fig ).

Notochaetae present from chaetiger 3 to posterior chaetigers, homogomph spinigers present throughout. Supra-acicular fascicle of neuropodia: homogomph spinigers and medium-sized blade heterogomph falcigers with serrations present throughout. Subacicular fascicle of neuropodia: medium-sized blade heterogomph falcigers with serrations and heterogomph spinigers present throughout ( Fig. 17H View Fig , Table 2).

Pygidium with anus crenulated; anal cirri cirriform, as long as last 7 chaetigers.

Type locality: Jihuei, Taitung County, Taiwan.

Distribution: Known only from the type locality.

Remarks: Perinereis pangcahae sp. nov. is included in group 1A by having one bar-shaped paragnath on area VI of the pharynx and not greatly expanded notopodial dorsal ligule on posterior chaetigers ( Hutchings et al. 1991: 271) ( Fig. 17D, G View Fig , Table 2). Of the seven species in this group reported from East and South Asia (see the Remarks section in P. houbihuensis sp. nov. for the name of these seven species), P. pangcahae sp. nov. is similar to P. cultrifera ( Grube, 1840) and P. helleri ( Grube, 1878) , which all have lateral teeth on area III and 3 cones on area V ( Fauvel 1915: 7; Horst 1924: 174; Hutchings et al. 1991: 250, 253, 255; de Leon-Gonzalez and Solis-Weiss 1998: 684; Park and Kim 2017: 256, 258, tables 2, 4). However, P. pangcahae sp. nov. differs from P. cultrifera by having: 1) greater number of paragnaths on area III (22–27 versus 5–11 or 10–12); 2) chevron-shaped bar on area VI (versus short straight bar); 2) ɔc-shaped ridge pattern of areas VI – V – VI (versus λ-shaped ridge pattern); 3) one large irregular-shaped glandular mass on posterior chaetigers (versus); 4) no notopodial prechaetal lobe on chaetigers of all body regions (versus present on anterior chaetigers); 5) neuroacicular ligule with predominant inferior lobe on anterior chaetigers (versus equal superior and inferior lobes); and 6) shorter serrations on the blade of heterogomph falcigers on neuropodia ( Fig. 17D–H View Fig , Table 2; Hutchings et al. 1991: 253–254, fig. 8a–c; Park and Kim 2017: 257, figs. 3A, 4C, 5F, table 4).

Perinereis pangcahae sp. nov. can be distinguished from P. helleri View in CoL by having: 1) greater number of paragnaths on areas III and IV (22–27 and 19–33 versus 11–20 and 10–19, respectively); 2) chevron-shaped bar on area VI (versus long straight bar); 3) ɔc-shaped ridge pattern of areas VI–V–VI (versus u-shaped ridge pattern); 4) dorsal cirri attached 1/3 to base of dorsal ligule on anterior chaetigers (versus medially attached to dorsal ligule); 5) the center and proximal lobes of dorsal ligule with one large irregular-shaped glandular mass on posterior chaetigers (versus absent); and 6) neuroacicular ligule with predominant inferior lobe on anterior chaetigers (versus equal superior and inferior lobes) ( Fig. 17D–H View Fig , Table 2; Hutchings et al. 1991: 255, fig. 9a–c; Park and Kim 2017: 255–256, 258, figs. 3B, 2, 4E, 5C2, table 4). The differences between P. pangcahae sp. nov. and four other new species of the 1A group described in the present study are discussed below.

Perinereis pseudocultrifera sp. nov. ( Fig. 18 View Fig , Table 2) urn:lsid:zoobank.org:act:FCC51AFF-F9B8-4607-AABA-D34AF9B7A5CB

Material examined: Holotype, NSNM 8748-127 , Wuchi Harbor (23°13.70'N, 121°25.08'E), habitat type: SRHB, 7 July 2015 GoogleMaps . Paratype: 1 specimen, NMNS 8748-128, Bisha Harbor (25°08.75'N, 121°47.17'E), habitat type: SRHB, 20 July 2016. Non-types: 1 specimen, NMNS 8748-129, Wuchi Harbor (23°13.70'N, 121°25.08'E), habitat type: SRHB, 7 July 2015; 1 specimen, NMNS 8748-130, Wuchi Harbor (23°13.70'N, 121°25.08'E), habitat type: SRHB, 5 October 2015; 1 specimen, NMNS 8748-131, Bisha Harbor (25°08.75'N, 121°47.17'E), habitat type: SRHB, 20 July 2016.

Etymology: The name is derived from the fusion of the Greek “ pseudȇs ” (false, deceptive) and the Latin “ cultrifera ”, referring to that the species shows a series of affinities to Perinereis cultrifera .

Description: Based on holotype ( NSNM 8748- 127, complete; atoke), paratypes ( NMNS 8748-128, complete; atoke) and non-types ( NMNS 8748-129–131, incomplete specimens; all atoke): Body length 48.0 (24.5) mm with 86 (68) chaetigers, chaetiger 10 width 1.9 (1.0–2.3, n = 4) mm, excluding parapodia; beige in alcohol ( Fig. 18A, B View Fig ). Prostomium wider than long, lateral antennae antero-lateral, shorter than palps, palpophores globose, palpostyles spheroid. Four pairs of tentacular cirri, longest one reaching chaetiger 3 (2–4, n = 4). Two pairs of eyes, in trapezoidal arrangement. Tentacular belt about 1.3x (1.1–1.3x, n = 4) longer than chaetiger 1. Pharynx with dark brown jaws, each with 6–7 (5–8, n = 4) teeth; paragnath pattern: I = 2 (1–3, n = 4) (same sample size on remaining areas), in cluster; II = 9 (9–11) (left), 9 (8–11) (right), in 2 (2–3) oblique rows; III = 8 (11–14) (center region with 6 (7–11) cones, in 2 (3) in oval-shaped patch; 2 lateral regions, each with 1 (0–4) cones; IV = 16 (15–21) (left), 17 (12–25) (right), in 3 (3–4) oblique rows, without bars; V = 0; VI = 1 (left), 1 (right), short bars; VII –VIII = 31 (30–35) cones, in 2 rows. Ridge pattern of areas VI – V – VI, λ-shaped ( Fig. 18A, B View Fig , Table 2).

Dorsal cirri digitiform, medially attached to dorsal ligule, about 0.7–0.8x as long as dorsal ligule on anterior to mid-body chaetigers, attached 2/3 to base of dorsal ligule on posterior chaetigers, about 0.4x as long as dorsal ligule on posterior chaetigers ( Fig. 18C–E View Fig , Table 2).

Dorsal ligule subconical throughout, about 2.9x longer than median ligule on anterior chaetigers, about 1.7x longer than median ligule on mid-body chaetigers, about 2.3x longer than median ligule on posterior chaetigers; center and proximal lobes with one large irregular-shaped glandular mass on mid-body to posterior chaetigers ( Fig. 18C–E View Fig , Table 2). Notopodial prechaetal lobe present throughout ( Fig. 18C–E View Fig , Table 2).

Median ligule conical, about as long as neuroacicular ligule on anterior chaetigers, subconical on mid-body to posterior chaetigers, about 1.4x longer than neuroacicular ligule on mid-body chaetigers, about 1.6x as long as neuroacicular ligule on posterior chaetigers ( Fig. 18C–E View Fig ).

Neuroacicular ligule with predominant inferior lobe, about 0.5x as long as ventral ligule on anterior chaetigers, inferior and superior lobes subequal in length on mid-body to posterior chaetigers, about 0.6–0.7x as long as ventral ligule. Neuropodial postchaetal lobe absent. Ventral ligule subconical throughout. Ventral cirri mid-ventrally attached to ventral edge of parapodia, about 0.8x as long as ventral ligule on anterior to mid-body chaetigers, about 0.9x as long as ventral ligule on posterior chaetigers ( Fig. 18C–E View Fig ).

Notochaetae present from chaetiger 3 to posterior chaetigers, homogomph spinigers present throughout. Supra-acicular fascicle of neuropodia: homogomph spinigers and short-bladed heterogomph falcigers with serrations present throughout. Subacicular fascicle of neuropodia: short-bladed heterogomph falcigers with serrations and heterogomph spinigers present throughout ( Fig. 18F–I View Fig , Table 2).

Pygidium with anus crenulated; anal cirri cirriform, as long as last 2 chaetigers.

Type locality: Wuchi Harbor, Taichung City, Taiwan.

Distribution: Known only from type locality and Bisha Harbor, New Taipei City, Taiwan.

Remarks: Perinereis pseudocultrifera sp. nov. can be included in group 1A of the genus based on the presence of one bar-shaped paragnath on area VI of the pharynx and not greatly expanded dorsal ligule on posterior chaetigers ( Hutchings et al. 1991: 271) ( Fig. 18A, E View Fig , Table 2). Of the seven species in this group reported from East and South Asia (see the Remarks section in P. houbihuensis sp. nov. for the name of these seven species), only P. cultrifera ( Grube, 1840) is similar to P. pseudocultrifera sp. nov. in terms of having similar paragnath patterns on areas I, II, III, IV, VI and VII –VIII, similar dorsal notopodial morphology, and neuropodial heterogomph spinigers present on chaetigers of all body regions ( Fig. 18A– C, F, G View Fig , Table 2; Hutchings et al. 1991: 250, 253, 255; Park and Kim 2017: 255–258, tables 2, 4). However, P. pseudocultrifera sp. nov. can be distinguished from P. cultrifera by having: 1) no paragnaths on area V (versus 2–5); 2) notopodial prechaetal lobe present on chaetigers of all body regions (versus present only on anterior chaetigers); 3) conical median ligule on anterior chaetigers (versus subconical); 4) neuroacicular ligule with predominant inferior lobe on anterior chaetigers (versus subequal inferior and superior lobes); and 5) short-bladed neuropodial heterogomph falcigers (versus medium-sized blade) ( Fig. 18A–I View Fig , Table 2; Hutchings et al. 1991: 253, fig. 8a–c; Park and Kim 2017: 258, table 4). The differences between P. pseudocultrifera sp. nov. and four other new species of group 1A described in the present study are discussed below.

Interestingly, P. pseudocultrifera sp. nov. and P. floridana ( Ehlers, 1868) are the only two Perinereis species found in subtidal fouling community on cement pier surface of Wuchi Harbor, Taichung City, west-central Taiwan. Morphologically, P. pseudocultrifera sp. nov. is somewhat similar to P. floridana but can be readily distinguished from the latter species by having: 1) lateral teeth on area III (versus absent); 2) no conical paragnaths on area V (versus 1 conical paragnath); and 3) notopodial prechaetal lobe present on chaetigers of all body regions (versus absent) ( Figs. 5A–G View Fig , 18A–E View Fig , Table 2; de León-González and Solís-Weiss 1998: 684, figs. 6A–E, 7A–E; de León-González and Goethel 2013: 7).

Perinereis qiguensis sp. nov. ( Fig. 19 View Fig , Table 3) urn:lsid:zoobank.org:act:AF8AB19D-BFE4-4328-9696-EE7294590FEA

Material examined: Holotype, NSNM 8748-132 , Qigu (23°04.70'N, 120°02.46'E), habitat type: ISSB, 20 January 1993. GoogleMaps

Etymology: The name is derived from the Qigu lagoon, where the worm was collected.

Description: Holotype: atoke, complete, body length 39.0 mm with 96 chaetigers, chaetiger 10 width 1.5 mm, excluding parapodia; beige in alcohol ( Fig. 19A View Fig ). Prostomium wider than long, lateral antennae antero-lateral, longer palps, palpophores globose, palpostyles spheroid. Four pairs of tentacular cirri, longest one reaching chaetiger 6. Two pairs of eyes, in trapezoidal arrangement. Tentacular belt about 1.3x longer than chaetiger 1. Pharynx with dark brown jaws, each with 5 teeth; paragnath pattern: I = 5, in nearly transverse row; II = 21 (left), 23 (right), in 2–3 oblique rows; III = 30 (center region with 16 cones, in 4 transverse rows; 2 lateral regions, each with 3 cones, in longitudinal line); IV = 22 (left), 23 (right), in 3–4 oblique rows, without bars; V = 3, in transverse row; VI = 7 (2 long bars at both end; 5 short bars in between long bars) (left), 6 (2 long bars, 1 outermost, 1 next to outermost; 4 short bars with 3 in between long bars, 1 outermost) (right), in shallow u-shaped line; VII –VIII = 36, in 2–3 rows. Ridge pattern of areas VI – V – VI, λ-shaped ( Fig. 19B View Fig , Table 3).

Dorsal cirri digitiform, attached 1/3 to base of dorsal ligule on anterior to mid-body chaetigers, about 0.6–0.7x as long as dorsal ligule, medially attached to dorsal ligule on posterior chaetigers, about 0.5x as long as dorsal ligule on posterior chaetigers ( Fig. 19C–E View Fig , Table 3).

Dorsal ligule subconical, not greatly elongated throughout, about 2.0–2.2x longer median ligule on anterior to posterior chaetigers, center lobe of dorsal ligule with one oval-shaped glandular mass on posterior chaetigers ( Fig. 19C–E View Fig ). Notopodial prechaetal lobe present throughout ( Fig. 19C–E View Fig , Table 3).

Median ligule conical throughout, about 1.2x longer than neuroacicular ligule on anterior chaetigers, about 1.5–1.6x longer than neuroacicular ligule on mid-body to posterior chaetigers ( Fig. 19C–E View Fig ).

Neuroacicular ligule with predominant inferior lobe on anterior chaetigers, inferior and superior lobes subequal in length on mid-body to posterior chaetigers, about 0.7x as long as ventral ligule on anterior to mid-body chaetigers, about as long as ventral ligule on posterior chaetigers. Neuropodial postchaetal lobe absent. Ventral ligule subconical throughout. Ventral cirri basally attached to ventral edge, about 0.8–0.9x as long as ventral ligule on anterior to mid-body chaetigers, about as long as ventral ligule on posterior chaetigers ( Fig. 19C–E View Fig ).

Notochaetae present from chaetiger 3 to posterior chaetigers, homogomph spinigers present throughout. Supra-acicular fascicle of neuropodia: homogomph spinigers and short-bladed heterogomph falcigers with serrations present throughout. Subacicular fascicle of neuropodia: short-bladed and medium-sized blade heterogomph falcigers with serrations present throughout, heterogomph spinigers present only on mid-body to posterior chaetigers ( Fig. 19F–J View Fig , Table 3).

Pygidium with anus crenulated; anal cirri cirriform, as long as last 6 chaetigers.

Type locality: Qigu Lagoon, Tainan City, Taiwan.

Distribution: Known only from type locality.

Remarks: Perinereis qiguensis sp. nov. belongs to group 3A, as well as the Perinereis nuntia species group, by having an arc of 6–7 bar-shaped paragnaths on area VI of the pharynx and not greatly expanded notopodial dorsal ligule on posterior chaetigers ( Fig. 19B, E View Fig , Table 3; Hutchings et al. 1991: 271; Wilson and Glasby 1993: 259; Glasby and Hsieh 2006: 558; Villalobos-Guerrero 2019: 468). Of the 20 known species in this species group recognized by Villalobos-Guerrero (2019), only P. mictodonta ( Marenzeller, 1879) and P. wilsoni Glasby and Hsieh, 2006 are somewhat similar to P. qiguensis sp. nov., because all have uneven bar-shaped paragnaths and five to six paragnaths on area VI, as well as lateral paragnaths on area III ( Figs. 15B View Fig , 19B View Fig ; Glasby and Hsieh 2006: 562, table 2; Villalobos-Guerrero 2019: 489). However, P. qiguensis sp. nov. can be distinguished from P. mictodonta by having: 1) λ-shaped ridge pattern of areas VI – V – VI (versus χ-shaped pattern); 2) smaller length ratio of dorsal cirri to dorsal ligule on anterior and posterior chaetigers (about 0.6 and about 0.5 versus 1.07 and 1.04, respectively); 3) one large, oval-shaped glandular mass in the center lobe of dorsal ligule on posterior chaetigers (versus one irregular-shaped glandular mass in each of the center and proximal lobes); 4) notopodial prechaetal lobe present on chaetigers of all body regions (versus absent); and 5) neuropodial heterogomph spinigers present only on mid-body to posterior chaetigers (versus present on all chaetigers) ( Fig. 15B–F View Fig , 19B–I View Fig , Table 3; Glasby and Hsieh 2006: 560–561, fig. 5C–D; Villalobos-Guerrero 2019: 489).

Perinereis qiguensis sp. nov. differs from P. wilsoni View in CoL by having: 1) more paragnaths on area I (5 versus 1–3); 2) λ-shaped ridge pattern of areas VI–V–VI (versus χ-shaped ridge pattern); 3) smaller length ratio of dorsal cirri to dorsal ligule on anterior and posterior chaetigers (about 0.6 and about 0.5 versus 1.43 and 2.35, respectively); 4) one large, oval-shaped glandular mass in the center lobe of dorsal ligule on posterior chaetigers (versus one irregular-shaped glandular mass in each of the center and proximal lobes); and 5) neuropodial heterogomph spinigers present only on mid-body to posterior chaetigers (versus present on all chaetigers) ( Fig. 19B–I View Fig , Table 3; Glasby and Hsieh 2006: 560–561, 572, figs. 5C–D, 10C–D, table 2; Villalobos-Guerrero 2019: 489). The differences between P. qiguensis sp. nov. and eight other new species of group 3A described in the present study are discussed below.

Perinereis taitungensis sp. nov. ( Fig. 20 View Fig , Table 2) urn:lsid:zoobank.org:act:95B3090A-8AC9-4E1E-8568-871D6F9770FE

Material examined: Holotype, NSNM 8748-133 , Jialulan (22°48.36'N, 121°11.92'E), habitat type: IRHB, 19 August 2012 GoogleMaps . Paratype: 1 specimen, NSNM 8748- 134, Jihuei (23°06.87'N, 121°24.21'E), habitat type: IRHB, 27 March 2014.

Etymology: The name is derived from the name of the county, Taitung, eastern Taiwan, where with the worm was collected.

Description: Based on holotype ( NSNM 8748- 133, complete; atoke) and paratype ( NSNM 8748- 134, incomplete; atoke): body length 84.0 mm with 139 chaetigers, chaetiger 10 width 3.3 mm, excluding parapodia; beige with brown spots on dorsal body edge and base of dorsal ligule on mid-body to posterior chaetigers in alcohol ( Fig. 20A, D, E View Fig ). Prostomium wider than long, lateral antennae antero-lateral, shorter than palps, palpophores globose, palpostyles spheroid. Four pairs of tentacular cirri, longest one reaching chaetiger 2. Two pairs of eyes, in trapezoidal arrangement. Tentacular belt about 1.4x longer than chaetiger 1. Pharynx with dark brown jaws, each with 3 teeth; paragnath pattern: I = 2 (2), in longitudinal line; II = 6 (6) (left), 11 (8) (right), in 2–3 (2) oblique rows; III = 19 (13) (center region with 14 (9) cones, in 4 transverse rows; 2 lateral regions, each with 2 (2) or 3 (2) cones, in longitudinal line); IV = 25 (19) (left), 26 (24) (right), in 4 oblique rows; V = 3 (3 large cone + 1 small cone), in triangle (small cone posteriorly to 3 large cones); VI = 1 (0) (left), 1 (1) (right), shield-shaped bars; VII –VIII = 28 (30), in 3 rows. Ridge pattern of areas VI – V – VI, ɔc-shaped ( Fig. 20B, C View Fig , Table 2).

Dorsal cirri digitiform, attached 1/3 to base of dorsal ligule in anterior chaetigers, about 0.8x as long as dorsal ligule, attached 2/3 to base of dorsal ligule in mid-body to posterior chaetigers, about 0.4x as long as dorsal ligule ( Fig. 20F–H View Fig , Table 2).

Dorsal ligule subconical throughout, as long as median ligule on anterior to mid-body chaetigers, about 1.9x longer than median ligule on posterior chaetigers; center and proximal lobes of dorsal ligule each with orange brownish, triangle-shaped, glandular mass on mid-body to posterior chaetigers ( Fig. 20F–H View Fig ). Notopodial prechaetal lobe present only on mid-body chaetigers ( Fig. 20F–H View Fig , Table 2).

Median ligule subconical throughout, slightly longer than neuroacicular ligule throughout ( Fig. 20F– H View Fig ).

Neuroacicular ligule with predominant inferior lobe on anterior to mid-body chaetigers, subequal inferior and superior lobes on posterior chaetigers, slightly shorter than ventral ligule on anterior to mid-body chaetigers, as long as ventral ligule on posterior chaetigers. Neuropodial postchaetal lobe absent. Ventral ligule subconical throughout. Ventral cirri digitiform, mid-ventrally attached to ventral edge of parapodia, about 0.7x as long as ventral ligule throughout ( Fig. 20F–H View Fig ).

Notochaetae present from chaetiger 3 to posterior chaetigers, homogomph spinigers present throughout. Supra-acicular fascicle of neuropodia: homogomph spinigers and short-bladed heterogomph falcigers with serrations present throughout. Subacicular fascicle of neuropodia: medium-sized blade heterogomph falcigers with serrations present throughout, heterogomph spinigers present on mid-body to posterior chaetigers ( Fig. 20I–L View Fig , Table 2).

Pygidium with anus crenulated; anal cirri cirriform, as long as last 3 chaetigers.

Type locality: Jialulan, Taitung County, Taiwan.

Distribution: Known only from type locality and Jihuei, Taitung County, Taiwan.

Remarks: Perinereis taitungensis sp. nov. has one bar-shaped paragnath on area VI and not greatly expanded notopodial dorsal ligule on posterior chaetigers, suggesting it can be categorized in group 1A ( Hutchings et al. 1991: 271) ( Fig. 20B, H View Fig , Table 2). Of the seven species in this group reported from East and Southeast Asia (see the Remarks section in P. houbihuensis sp. nov. for the name of these seven species), only P. cultrifera ( Grube, 1840) , P. euiini Park and Kim, 2017 , and P. helleri ( Grube, 1878) is similar to P. taitungensis sp. nov., which all have 3 cones on area V ( Fauvel 1915: 7; Horst 1924: 174; Hutchings et al. 1991: 250, 253, 255; de León-González and Solís-Weiss 1998: 684; Park and Kim 2017: 256, 258, tables 2, 4). However, P. taitungensis sp. nov. can be distinguished from P. cultrifera by having: 1) ɔc-shaped ridge pattern of V – VI – V (versus λ-shaped ridge pattern); 2) notopodial prechaetal lobe present only on mid-body chaetigers (versus present on anterior to mid-body chaetigers); 3) smaller length ratio of dorsal ligule to median ligule on posterior chaetigers (1.8 versus 2.2); and 4) the center and proximal lobes of dorsal ligule each with orange brownish, triangle-shaped, glandular masses on posterior chaetigers (versus beige, oblong glandular masses); 5) neuropodial heterogomph spinigers present only on mid-body to posterior chaetigers (versus present on chaetigers of all body regions) ( Figs. 3E View Fig , 20H–K View Fig , Table 2; Hutchings et al. 1991: 253–254, fig. 8a–c; Park and Kim 2017: 256, fig. 5F).

Perinereis taitungensis sp. nov. can be readily distinguished from P. euiini View in CoL by the presence of lateral teeth on area III (versus absent) ( Park and Kim 2017: 256, fig. 4A). The other key characters for differentiating P. taitungensis sp. nov. from P. euiini View in CoL include: 1) presence of one orange brownish, triangle-shaped, glandular masses in each of the center and proximal lobes of dorsal ligule on mid-body to posterior chaetigers (versus absent); 2) not greatly expanded dorsal ligule on posterior chaetigers (versus greatly expanded); and 3) presence of neuropodial heterogomph spinigers on chaetigers of mid to posterior body regions (versus present on chaetigers of all body regions) ( Fig. 20H–K View Fig , Table 2; Park and Kim 2017: 257, figs. 2C–I, 3A, 5A).

Perinereis taitungensis sp. nov. differs from P. helleri View in CoL by having: 1) more paragnaths on area IV (19–26 versus 10–19); 2) the center and proximal lobes of dorsal ligule each with one orange brownish, triangle-shaped, masses on mid-body to posterior chaetigers (versus absent); 3) notopodial prechaetal lobe present on mid-body chaetigers (versus absent); and 4) neuropodial heterogomph spinigers present only on mid-body to posterior chaetigers (versus present on chaetigers of all body regions) ( Fig. 20H–K View Fig , Table 2; Hutchings et al. 1991: 255, fig. 9a, b; Park and Kim 2017: 255–256, figs. 3B, 4E, 5C).

Perinereis tubicola sp. nov. ( Fig. 21 View Fig , Table 3) urn:lsid:zoobank.org:act:AB171A57-CAB5-4A5D-BF86-024ECF43793D

Material examined: Holotype, NSNM 8748-135 ,

Wanlitong (21°59.73'N, 120°42.26'E), habitat type: IRHB, coll. K.S. Lee, January 1991.

Etymology: The name is derived from the encrypted living condition of the worm in its own secreted tube.

Description: Holotype, atoke, without posterior end, remaining body length 198.0 mm with 162 chaetigers, chaetiger 10 width 5.3 mm, excluding parapodia; beige in alcohol ( Fig. 21A View Fig ). Prostomium wider than long, lateral antennae antero-lateral, shorter than palps, palpophores globose, palpostyles spheroid. Four pairs of tentacular cirri, longest one reaching chaetiger 3. Two pairs of eyes, in trapezoidal arrangement, without dark pigment in alcohol. Tentacular belt longer than chaetiger 1. Pharynx with dark brown jaws, each with 4 teeth; paragnath pattern: I = 1 small cone; II = 2 (left), 1 (right), small cones; III = 0; IV = 2 (left), 3 (right), small cones, without bars; V = 3 small cones; VI = 9 (left), 8 (right), uneven-length short bars in transverse row; VII –VIII = 12 small cones, in 1 row. Ridge pattern of areas VI – V – VI, u-shaped ( Fig. 21B View Fig , Table 3).

Dorsal cirri digitiform, medially attached to dorsal ligule throughout, about as long as dorsal ligule on anterior chaetigers, about 0.6–0.8x as long as dorsal ligule on mid-body to posterior chaetigers ( Fig. 21C–E View Fig , Table 3).

Dorsal ligule subconical throughout, about 1.4–1.5x longer than dorsal ligule on anterior to mid-body chaetigers, about 2.5x longer than dorsal ligule on posterior chaetigers ( Fig. 21C–E View Fig ). Notopodial prechaetal lobe absent ( Table 3).

Median ligule subconical throughout, as long as neuroacicular ligule on anterior chaetigers, about 2.7x longer than neuroacicular ligule on mid-body chaetigers, about 1.6x long than neuroacicular ligule on posterior chaetigers ( Fig. 21C–E View Fig ).

Neuroacicular ligule with predominant inferior lobe on anterior to mid-body chaetigers, inferior and superior lobes subequal in length on posterior chaetigers, about as long as ventral ligule throughout. Neuropodial postchaetal lobe absent. Ventral ligule subconical throughout. Ventral cirri mid-ventrally attached to ventral edge of parapodia, about 0.8x as long as ventral ligule on anterior chaetigers, about 0.4–0.5x as long as ventral ligule on posterior chaetigers ( Fig. 21C–E View Fig ).

Notochaetae present from chaetiger 3 to posterior chaetigers, homogomph spinigers present throughout. Supra-acicular fascicle of neuropodia: homogomph spinigers and short-bladed heterogomph falcigers with serrations present throughout. Subacicular fascicle of neuropodia: short-bladed heterogomph falcigers with serrations present throughout ( Fig. 21F, G View Fig , Table 3), heterogomph spinigers present on mid-body to posterior chaetigers ( Fig. 21H View Fig , Table 3).

Type locality: Wanlitong, Pingtung County, Taiwan.

Distribution: Known only from type locality.

Remarks: Perinereis tubicola sp. nov. has an arc of 8–9 bar-shaped paragnaths on area VI of the pharynx and not greatly expanded notopodial dorsal ligule on posterior chaetigers; it belongs to group 3A and the Perinereis nuntia species group ( Fig. 21B, E View Fig , Table 3; Hutchings et al. 1991: 271; Wilson and Glasby 1993: 259; Glasby and Hsieh 2006: 558; Villalobos-Guerrero 2019: 468). Of the 20 known species of the Perinereis nuntia group recognized by Villalobos-Guerrero (2019), Perinereis tubicola sp. nov. easily distinguished from the known congeners of this species group by having no paragnath on area III and the fewest number of paragnaths on areas I, II, IV, and VII –VIII ( Table 3; Glasby and Hsieh 2006: 562, table 2; Villalobos-Guerrero 2019: 489). The differences between P. tubicola sp. nov. and eight other new species of the 3A group described in the present study are discussed below.