Meiodorvillea penhae, Bonaldo & Steiner & Amaral, 2022

Bonaldo, Rafael de Oliveira, Steiner, Tatiana Menchini & Amaral, Antônia Cecília Zacagnini, 2022, Revision of Meiodorvillea Jumars, 1974 (Annelida: Dorvilleidae) including descriptions of three new species from the Southwestern Atlantic Ocean, PLoS ONE (e 0264081) 1974 (3), pp. 1-27 : 12-17

Meiodorvillea penhae sp. nov.

( Figs 8–12 , Table 1 )

urn:lsid:zoobank.org:act:60CC2B5E-ED78-4497-85CD-BE63CFD14EF6

Type locality. Southwest Atlantic Ocean , 18˚36’31.68"S 39˚9’33"W, off Espírito Santo State, Brazil, 39 m depth .

Type material examined. Holotype: State of Espírito Santo – ZUEC-POL 21359 18˚ 36’31.68"S 39˚9’33"W, 39 m, sand, 17 Jan 2012 . Paratypes: State of Espírito Santo – ZUEC-POL 21360 (3 specs/1 incomplete), 18˚36’31.68"S 39˚9’33"W, 39 m, sand, 17 Jan 2012 ; ZUEC-POL 21361 (4 specs) 20˚12’21.46"S 39˚58’0.3"W, 50 m, sand with biodetritus, 13 Jul 2013 ; ZUEC-POL 21362 (2 specs) 20˚1’3.73"S 39˚50’13.76"W, 53 m, sand with rhodoliths, 16 Dec 2010 ; ZUEC-POL 21363 (1 spec) 19˚49’7.27"S 39˚36’8.52"W, 158 m, muddy sand, 17 Jan 2012 ; ZUEC-POL 21364 (3 specs) 18˚40’55.3"S 38˚55’41.48"W, 55 m, sand, 17 Jan 2012 . State of Rio de Janeiro – ZUEC-POL 21365 (5 specs) 21˚22’58.61"S 40˚19’41.01"W, 53 m, 21 Jul 2009 .

(m = meters depth).

Other material examined. State of Espírito Santo – ZUEC-POL 21366 (1 spec) 19˚ 42’26.81"S 39˚39’5.27"W, 39 m, sand, 15 Jul 2011 ; ZUEC-POL 21367 (1 spec) 19˚41’24.99"S 39˚31’20.42"W, 53 m, fine sand, 13 Jul 2011 ; ZUEC-POL 21368 (1 spec) 20˚11’25.35"S 40˚ 2’16.02"W, 39 m, mud, 20 Jan 2012 ; ZUEC-POL 21369 (1 spec) 19˚37’41.83"S 39˚35’31.52"W, 41 m, sand, 15 Jul 2011 ; ZUEC-POL 21370 (8 specs) 18˚53’29.72"S 39˚6’23.3"W, 52 m, sand, 18 Jan 2012 ; ZUEC-POL 21371 (10 specs/1 incomplete) 18˚52’32.61"S 39˚8’42.82"W, 40 m, muddy sand, 18 Jan 2012 ; ZUEC-POL 21372 (2 specs) 18˚40’55.3"S 38˚55’41.48"W, 55 m, sand, 17 Jan 2012 ; ZUEC-POL 21373 (1 spec) 20˚34’53.42"S 40˚6’27.43"W, 50 m, sand, 21 Jan 2012 ; ZUEC-POL 21374 (1 spec) 20˚34’32.47"S 40˚20’52.37"W, 25 m, mud, 21 Jan 2012 ; ZUEC-POL 21375 (2 specs) 19˚26’5"S 39˚17’38.92"W, 50 m, muddy sand, 19 Jan 2012 ; ZUEC-POL 21376 (3 specs) 21˚4’1.29"S 40˚18’50.11"W, 49 m, mud with biodetritus, 22 Jan 2012 ; ZUEC-POL 21379 (1 spec) 18˚36’32.45"S 39˚9’32.83"W, 40 m, sand, 02 Jul 2013 ; ZUEC-POL 21380 (1 spec) 18˚40’57.41"S 38˚55’39.92"W, 53 m, sand, 02 Jul 2013 ; ZUEC-POL 21381 (1 spec) 19˚55’44.66"S 39˚45’38.7"W, 51 m, rhodoliths with mud, 16 Dec 2010 ; ZUEC-POL 21382 (1 incomplete spec) 19˚41’33.92"S 39˚31’17.74"W, 54 m, sand, 12 Dec 2010 ; ZUEC-POL 21383 (1 spec) 21˚10’16.281"S 40˚45’58.437"W, 21 m, 22 Jul 2009 ; ZUEC-POL 21383 (2 specs) 19˚9’51.36"S 39˚29’20.53"W, 27 m, sand, 15 Jul 2013 ; ZUEC-POL 21385 (1 spec) 19˚26’4.81"S 39˚17’38.64"W, 50 m, muddy sand, 14 Jul 2013 ; ZUEC-POL 21386 (1 spec) 18˚52’31.35"S 39˚ 8’41.34"W, 40 m, calcareous, 15 Jul 2013 ; ZUEC-POL 21387 (1 spec) 20˚34’34.37"S 40˚ 20’50.77"W, 26 m, mud, 12 Jul 2013 ; ZUEC-POL 21388 (2 specs) 20˚34’53.05"S 40˚6’27.68"W, 49 m, sand with biodetritus, 12 Jul 2013 ; ZUEC-POL 21389 (1 spec) 19˚52’35.48"S 39˚ 49’5.63"W, 43 m, sand, 16 Dec 2010 ; ZUEC-POL 21390 (1 spec) 19˚49’57.38"S 39˚52’14.02"W, 33 m, muddy sand, 15 Dec 2010 . State of Rio de Janeiro – ZUEC-POL 21377 (1 incomplete spec) 21˚22’58.813"S 40˚19’41.885"W, 52 m, 05 Mar 2009 ; ZUEC-POL 21378 (1 spec) 21˚ 22’58.347"S 40˚19’41.209"W, 53 m, 21 Jul 2009 . (m = meters depth).

SEM material. ZUEC-POL 21391 (3 spec)– State of Espírito Santo, 18˚36’31.68"S 39˚ 9’33"W, 39 m , sand, 17 Jan 2012; State of Espírito Santo, 18˚40’57.41"S 38˚55’39.92"W, 53 m ,

sand, 02 Jul 2013; State of Rio de Janeiro, 21˚22’58.975"S 40˚19’42.346"W, 52 m, 05 Mar 2009. (m = meters depth).

Diagnosis. One pair of antennae and one pair of palps. Dorsal cirrus absent. Ventral cirrus papilliform, absent in the first chaetiger. Chaetae capillary, furcate thick and symmetrical on chaetigers 1 to 7–9, replaced by geniculate towards the end of body, dorsalmost compound spiniger or falciger, median and ventralmost falcigers, and cultriform in last chaetigers in some specimens, replacing the ventralmost compound. Two pairs of pygidial cirri.

Description of the holotype. Complete specimen, 45 chaetigers, 2.2 mm long, 0.21 mm wide in anterior region, 0.14 mm in posterior region, excluding parapodia. Width uniform, anterior region slightly wider ( Fig 8A ). Color in ethanol pale yellow.

Prostomium pear-shaped, as long as wide, anterior half depressed and rounded, posterior half globular, wider than the anterior half ( Figs 8B and 9A–9D ); ciliary band between them ( Fig 9C ). Eyes absent. One pair of clavate antennae inserted dorsolaterally on middle posterior half of prostomium, half as long as prostomium ( Figs 8B , 9A and 9C ). Pair of small and clavate palps inserted laterally at prostomium base, 1/2 the antennae length ( Figs 8B and 9A–9C ).

Two peristomial rings, both as long as prostomium when not retracted into prostomium ( Figs 8B and 9A–9D ); posterior wider than anterior, covering it dorsally. Transversal ciliary bands at base of peristomium and anterior chaetigers ( Fig 9C ).

Cylindrical parapodia, short and robust at anterior region ( Figs 8C , 10A and 10B ), tapering towards posterior region ( Figs 8D , 10C and 10D ), ciliary tufts dorsally on parapodia ( Fig 10A ).

https://doi.org/10.1371/journal.pone.0264081.g012

Dorsal cirrus absent. Papilliform ventral cirrus, inserted medially in the parapodium, larger in posterior region ( Fig 10 ), absent in the first chaetiger.

Supra-acicular chaetae: (1) one long and serrated capillary ( Fig 11A ); (2) one thick furcate with short, stout, and symmetrical prongs with serrated base ( Figs 8C , 11B, 11H and 11K ), present in chaetigers 1 to 8, replaced by (3) one geniculate with serrated margin, shorter than capillary ( Figs 8D , 11C, 11D and 11I ). Sub-acicular chaetae: (4) three compound heterogomphs ( Fig 11E–11G and 11 J-11L), distal end of shafts serrated and blades unidentate with serrated cutting edge: dorsalmost longest with falcigerous or spinigerous blade, median facigerous, ventralmost falcigerous and shortest. Chaetae gradually slender and longer in posterior region. One internal thick acicula ( Fig 10B and 10D ).

Pygidium rounded and narrower than previous chaetigers. Two pairs of clavate pygidial cirri, dorsal pair twice as long as pygidium, ventral pair as long as pygidium ( Figs 8E , 9E and 9F ).

Jaw apparatus from additional non-type material with ventral and medially fused mandibles, anterior region enlarged with smooth margins without free or fused teeth, posterior region slender and curved ( Fig 12A and 12B ). Basal plates of maxillae with smooth inner margin, two subsymmetrical rows with 10 to 13 pairs of free rectangular and denticulate maxillary plates, each one with one posterior main fang and usually four anterior teeth, last and anteriormost plates larger and rounded, with small and more numerous teeth. ( Fig 12A and 12C ).

Variation. Complete specimens 1.67–3.09 mm long, 146–281 μm wide, 27–62 chaetigers. Anterior region of most specimens wider, some with moniliform segments on posterior region, some with both peristomial rings visible in dorsal view. Furcate chaeta from chaetigers 1 to 7–9. Many specimens, including paratypes, with cultriform chaeta randomly found on last chaetigers ( Fig 11G and 11L ), absent in holotype. Paired maxillary plates from 10 to 13 pairs.

Remarks. Meiodorvillea penhae sp. nov. has furcate chaeta in anterior region replaced by geniculate in median and posterior regions, differing from any other species of Meiodorvillea , but occurring in Gymnodorvillea floridana Wainright & Perkins, 1982 [ 31].

The poor condition of the specimens did not allow detecting the possible presence of basal ciliated bands in median and posterior chaetigers.

Meiodorvillea penhae sp. nov. resembles M. minuta in having antennae and palps of same length and as long as the prostomium. However, geniculate chaetae are only present in the former and dorsal cirri only in the latter. Meiodorvillea apalpata differs from both species in lacking palps and furcate chaetae. Meiodorvillea penhae sp. nov. apparently corresponds to morphotypes with rasper-like maxillary plates of Meiodorvillea sp. A , described by Wolf [ 19].

Geographic distribution and bathymetric range. Southwestern Atlantic Ocean , States of Espírito Santo and Rio de Janeiro ( Brazil), 21 to 158 m, in sand, muddy sand, sand with biodetritus, sand with rhodoliths, mud, mud with biodetritus and rhodoliths with mud .

Etymology. The specific epithet “ penhae ” refers to Our Lady of Penha, patron saint of the State of Espírito Santo.

Figures

Fig 8. Meiodorvillea penhae sp. nov. (A) complete specimen, dorsal view; (B) anterior region, dorsal view; (C) parapodia from anterior region with furcate chaeta, dorsal view; (D) parapodium from posterior region with geniculate chaeta, dorsal view; (E) pygidial region, ventral view. Abbreviations: an = antenna; dpc = dorsal pygidial cirrus; fc = furcate chaeta; gc = geniculate chaeta; pa = palp; vpc = ventral pygidial cirrus. Scale bars: (A) = 200 μm; (B,D) = 100 μm; (C,E) = 50 μm. https://doi.org/10.1371/journal.pone.0264081.g008

Fig 9. Meiodorvillea penhae sp. nov. (A,C) anterior region, dorsal view; (B) anterior region, ventral view; (D) anterior region, ventrolateral view; (E,F) pygidium, ventral view. Abbreviations: an = antenna; dpc = dorsal pygidial cirrus; pa = palp; vpc = ventral pygidial cirrus. Scale bars: (A,B,E) = 25 μm; (C) = 50 μm; (D) = 20 μm; (F) = 10 μm. https://doi.org/10.1371/journal.pone.0264081.g009

Fig 10. Meiodorvillea penhae sp. nov. (A,B) parapodia from anterior region; (C,D) parapodia from posterior region; all anterior view. Abbreviations: fc = furcate chaeta; gc = geniculate chaeta; vc = ventral cirrus. Scale bars: (A,C) = 15.6 μm; (B,D) = 10 μm. https://doi.org/10.1371/journal.pone.0264081.g010

Fig 11. Meiodorvillea penhae sp. nov. (A) capillary chaeta, anterior region; (B,H) furcate chaeta; (C,D,I) geniculate chaeta;(E) compound chaetae, anterior region; (F) compound chaetae, median region; (G) compound and cultriform chaetae, posterior region; (J) compound chaetae; (K) chaetae, anterior region; (L) chaetae, posterior region. Abbreviations: cc = cultriform chaeta. Scale bars: (A-G) = 6.25 μm; (H-I) = 5 μm; (J) = 2 μm; (K-L) = 10 μm. https://doi.org/10.1371/journal.pone.0264081.g011

Fig 12. Meiodorvillea penhae sp. nov. (A) jaw apparatus; (B) mandibles; (C) maxillae; all dorsal view. Abbreviations: bs = basal plate; cls = carrier-like structure; mf = main fang; mp = maxillary plates. Scale bars: (A) = 20 μm; (B) = 10 μm; (C) = 6.25 μm.