Ceratonereis mirabilis Kinberg, 1865

Conde-Vela, Víctor Manuel, 2021, Revision of Ceratonereis Kinberg, 1865 recorded from the Caribbean Sea, with description of two new Ceratonereis species and a new combination of Platynereis Kinberg, 1865, Zootaxa 5026 (3), pp. 301-343 : 305-309

publication ID	https://doi.org/ 10.11646/zootaxa.5026.3.1
publication LSID	lsid:zoobank.org:pub:ADCAF347-2787-4AEF-AE0F-B8D5B5968B66
persistent identifier	https://treatment.plazi.org/id/4E3F87EA-F421-FFAE-F89B-FB51FC55DE80
treatment provided by	Plazi
scientific name	Ceratonereis mirabilis Kinberg, 1865
status

Treatment

Ceratonereis mirabilis Kinberg, 1865 View in CoL

Figures 3–4 View FIGURE 3 View FIGURE 4

Ceratonereis mirabilis Kinberg 1865: 170 View in CoL . Hartman 1948: 71 (partim). Perkins 1980: 4–11, figs 1–4. Santos & Lana 2003: 6, figs 1–6. Bakken & Wilson 2005: 519.

Type material. Southwestern Atlantic Ocean, Brazil. Syntypes of Ceratonereis mirabilis SMNH 456 (2), 9º S Brazil, 33 m, 1852, Coll. Werngren.

Additional material. Southwestern Atlantic Ocean, Brazil. MNHN A886 About MNHN (1) , R / V Calypso, Sta. 14, F. Noronha, baie Sta. Antonio, 6–10 m, plongée, roche, coraux, 18 November 1961 . MNHN A886 About MNHN (1) , R / V Calypso, Sta. 23 (8°19’ S, 34°39’ W), drague, algues, coraux, 75 m, 21 November 1961 GoogleMaps . MNHN A886 About MNHN (1) , R / V Calypso, Sta. 31 (9º40’ S, 35°18’ W), drague, algues, 54– 47 m, 22 November 1961 GoogleMaps . MNHN A886 About MNHN (no specimen found) , R / V Calypso, Sta. 10 (3º51.5’ S, 33º51.5’ W), drague, roches, coraux, algues, 17 November 1961 GoogleMaps .

Description. Syntypes (SMNH 456) consists of four fragments in poor condition, very friable tissue, dissections were not attempted ( Fig. 3A View FIGURE 3 ); an anterior fragment 6 mm long, 0.8 mm wide at chaetiger 10 excluding parapodia, 29 chaetigers ( Fig. 3A, B View FIGURE 3 ), and its respective posterior end 6 mm long, 0.8 mm wide, 24 chaetigers ( Fig. 3A View FIGURE 3 ), used for number of paragnaths; another larger medium portion 5.8 mm long, 1 mm wide, 19 chaetigers, and a posterior end 4 mm long, 0.8 mm wide, 17 chaetigers. Additional material from Brazil (MNHN A886) in good condition ( Fig. 3C–E View FIGURE 3 ); one specimen dried (Sta. 23) and in two fragments; one specimen (Sta. 14) incomplete, most anterior cirri detached, 9 mm long, 1 mm wide at chaetiger 10 excluding parapodia, 42 chaetigers, used for description of parapodia and chaetae; one specimen (Sta. 31) incomplete, in good condition, 5.5 mm long, 1.5 mm wide at chaetiger 10 excluding parapodia, 11 chaetigers.

Body pale, without pigmentation, glandular masses not observed ( Fig. 3A–E View FIGURE 3 ).

Prostomium as long as wide, subpentagonal, anterior margin deeply incised, dorsal groove present ( Fig. 3A–E View FIGURE 3 ).

Antennae lanceolate, 1.5x long of prostomium, as long as or shorter than palps ( Fig. 3B–E View FIGURE 3 ).

Eyes rounded, subequal, in trapezoidal arrangement ( Fig. 3A–E View FIGURE 3 ).

Palpophores subcylindrical, longer than prostomium; tips of palpostyles rounded or pyriform ( Fig. 3A–E View FIGURE 3 ).

Achaetous ring as long as chaetiger 1, anterior margin convex ( Fig. 3A, D View FIGURE 3 ).

Tentacular cirri smooth, posterodorsal cirri extending backwards to chaetiger 15 ( Fig. 3B–E View FIGURE 3 ).

Pharynx everted in one syntype, examined by dissection in non-type. Jaws amber, 7 teeth present along cutting edge ( Fig. 4H View FIGURE 4 ). Maxillary ring cylindrical, oral ring frustum-shaped, 2–3x longer and 1.2x wider than maxillary ring ( Fig. 3B View FIGURE 3 ).

Maxillary ring: I= 0; IIa= 14 (14–15) and IIb= 16 (14–16) cones in arc; III= 11 (11–25) cones in ellipse; IVa= 12 (12–15) and IVb= 18 (15–18) cones in ellipse. Oral ring: V= 0; VIa-b= 1 rounded papilla; VII-VIII= 0. Ridge pattern of areas VI–V–VI, λ-shaped.

Paired oesophageal caeca absent.

Dorsal cirri filiform, progressively relatively longer; 4.7x longer than neuroacicular ligule in chaetiger 2, 5.7x longer in chaetiger 7, 8x longer in chaetiger 13, 10.3x longer in chaetiger 23, 9.3x longer in chaetiger 33 ( Fig. 4I–M View FIGURE 4 ).

Dorsal ligule subulate or digitiform, progressively shorter toward posterior chaetigers; 1.3x longer than neuroacicular ligule in chaetiger 7, 0.6x length of neuroacicular ligule in chaetiger 13, 0.7x length in chaetiger 23, 0.2x length in chaetiger 33 ( Fig. 4I–M View FIGURE 4 ).

Notopodial prechaetal lobe absent throughout ( Fig. 4I–M View FIGURE 4 ).

Median ligule subconical, blunt tip; 1.4x longer than neuroacicular ligule in chaetiger 7, 1.4x longer in chaetiger 13, 1.3x longer in chaetiger 23, as long as in chaetiger 33 ( Fig. 4I–M View FIGURE 4 ).

Neuroacicular ligule subconical throughout, progressively relatively shorter toward posterior chaetigers ( Fig. 4I–M View FIGURE 4 ). Neuropodial superior and inferior lobes absent ( Fig. 4I–M View FIGURE 4 ).

Neuropodial postchaetal lobe digitiform in anterior chaetigers, becoming lamelliform toward posterior chaetigers ( Fig. 4I–M View FIGURE 4 ).

Ventral ligule digitiform throughout, longer than neuroacicular ligule in anterior chaetigers, becoming shorter than toward posterior chaetigers; 3.6x longer than neuroacicular ligule in chaetiger 2, 1.2x longer in chaetiger 7, 1.3x longer in chaetiger 13, 0.6x length of neuroacicular ligule in chaetiger 23, 0.6x length in chaetiger 33 ( Fig. 4I–M View FIGURE 4 ).

Ventral cirrus filiform, extending beyond tip of neuroacicular ligule in posterior chaetigers; 2.8x longer than neuroacicular ligule in chaetiger 2, 2.6x longer in chaetiger 7, 2.3x longer in chaetiger 13, 2.4x longer in chaetiger 22 ( Fig. 4I–M View FIGURE 4 ).

Aciculae amber throughout. Notoaciculae present in first two chaetigers ( Fig. 4I View FIGURE 4 ). Notoaciculae narrower than neuroaciculae in anterior chaetigers, becoming as wide as in following chaetigers ( Fig. 4J–M View FIGURE 4 ).

Notochaetae both short-bossed heterogomph spinigers and falcigers; spinigers in all chaetigers, pectinate, teeth minute, decreasing in size toward tip ( Fig. 4A View FIGURE 4 ); falcigers appearing from chaetigers 15–16, pectinate, teeth coarse, distal teeth not extending beyond blade tip, blade tip with a distal tooth, giving a bifid appearance ( Fig. 4B, C View FIGURE 4 ), occasionally two falcigers with distinct blade size at the same chaetiger ( Fig. 4C View FIGURE 4 ), shaft becoming slightly stouter toward posterior chaetigers ( Fig. 4B, C View FIGURE 4 ).

Supracicular neurochaetae short-bossed heterogomph spinigers and long-bossed heterogomph falcigers; spinigers with blades as in notopodial ones; falcigers pectinate, teeth minute, distal teeth occasionally barely extending beyond blade tip, blade tip rounded along first 15–16 chaetigers, with a very small distal tooth thereafter, often nearly rounded ( Fig. 4D, F View FIGURE 4 ), blades becoming shorter toward posterior chaetigers ( Fig. 4D, F View FIGURE 4 ).

Infracicular neurochaetae both long-bossed heterogomph spinigers and falcigers; spinigers with blades as in notopodial ones; falcigers pectinate, teeth minute, distal teeth barely extending beyond blade tip, blade tip rounded along first 15–16 chaetigers, with a very small distal tooth thereafter, often nearly rounded, blades becoming shorter toward posterior chaetigers ( Fig. 4E, G View FIGURE 4 ).

Pygidium unknown.

Remarks. Treadwell (1901) thought that Nereis gracilis Webster, 1884 was a junior synonym of Ceratonereis mirabilis (as Nereis mirabilis ). Later, Hartman (1948) briefly redescribed C. mirabilis based on the type material and also concluded C. tentaculata , C. singularis , Nereis singularis Treadwell, 1943 (fide Hartman 1956), and Nereis gracilis (fide Hartman 1959) are junior synonyms of it. Perkins (1980) redescribed the species based on both type and non-type materials of several localities from the Caribbean Sea, recognized C. tentaculata as a valid species, and regarded Nereis gracilis Webster, 1884 as a junior synonym of it. After the examination of type and additional material from Brazil, C. mirabilis is restricted to Brazilian coasts, and the synonymy of N. gracilis is rejected and discussed in the remarks of the latter species. Synonymy of N. singularis with C. mirabilis and C. singularis is discussed in the remarks of the latter species.

The specimens of C. mirabilis recorded by Santos & Lana (2003) from Rocas Atoll, Brazil, match well with the current description. Ceratonereis mirabilis has been recorded several times from the Caribbean Sea ( Dean 2012). Perkins (1980) recorded C. mirabilis from Bermuda, Bahamas, Barbados, Florida, and Puerto Rico, but Bermudan specimens belong to C. gracilis and the remaining ones need to be re-assessed because likely they are C. nancyae n. sp.; records of C. mirabilis by Salazar-Vallejo & Jiménez-Cueto (1997) belong to C. nancyae n. sp.

Ceratonereis mirabilis sensu Imajima (1972) differs from C. mirabilis in the following features: 1) in Japanese specimens, dorsal ligules are longer than median ligules in anterior chaetigers, whereas in Brazilian ones they are shorter; 2) in Japanese specimens, dorsal ligules are relatively larger in posterior chaetigers than in Brazilian specimens; 3) in Japanese specimens, dorsal cirri are relatively shorter than in Brazilian ones. Atoke specimens from the South China Sea recorded by Wu et al. (1985) are similar to Japanese ones, except the jaws have indistinct teeth along the cutting edge, dorsal cirri are relatively longer, and ventral cirri extend beyond ventral ligules in the first two chaetigers. The same author excluded the presence of lobes in areas VI in the description, but they were represented in the drawing of the pharynx ( Imajima 1972, fig. 13b).

Fauvel (1939) recorded C. mirabilis from Vietnam after the presence of an anterior margin of prostomium deeply incised, long dorsal cirri and falcigers with long blades; also, he suggested specimens identified by Gravier & Dantan (1934) as Nereis (Ceratonereis) singularis , and their new species Nereis (Ceratonereis) incisa and Nereis (Ceratonereis) imperfecta , from Central Vietnam, are synonyms of C. mirabilis . Specimens used in those works were not studied here; re-evaluation of these specimens is needed to determine if they are C. mirabilis or C. singularis .

Day (1967) recorded C. mirabilis from Mozambique and Madagascar, but their specimens differ from Brazilian ones as follows: 1) in African specimens, the dorsum is minutely papillated, whereas in Brazilian ones it is smooth; 2) in African specimens, dorsal cirri are relatively shorter throughout the body than in Brazilian ones; 3) in African specimens, ventral cirri are shorter than ventral ligules in posterior chaetigers, whereas in Brazilian ones they are longer; 4) in African specimens, median ligules are shorter than neuroacicular ligules, whereas in Brazilian ones they are longer. Records of C. mirabilis from the Persian Gulf ( Fauvel 1911; 1918; 1919), the Australian ( Hutchings & Turvey 1982), Egyptian ( Abdelnaby 2020), Indian ( Pati et al. 2014; Sekar et al. 2016), and Mediterranean coasts ( Çinar 2005), and other regions, need to be addressed in future works.