Valencia 2020: 23–29 Scale-bearing beauty: Intertidal scale-worms (Polychaeta: Polynoidae) from Punta Blanca (Arequipa, Peru) Valencia-Soto, David Zootaxa 2021 2021-09-07 5032 2 151 194 6PCBH Monro 1928 [151,481,582,609] Polychaeta Polynoidae Lepidonotus Animalia Phyllodocida 4 155 Annelida species crosslandi   Figures 3–8     Lepidonotus sp.  Valencia 2020: 23–29, Figs 8–13.   Material examined.  MUSMNº 4590, 1 specimen, complete, Punta Blanca, Arequipa, Peru, 15°27’38.70”S 75°2’0.60”W, Station3B, coll. from rocky shore at low tide under rocks,  14 September 2019, by D. Valencia-Sotoand D. Valencia-Valencia, pharynx dissected and dissolved for jaw complete examination.  MUSMNº 4591, 6 specimens, same sampling data, specimens with non-everted pharynges dissected for superficial jaw examination.  MUSMNº 4635, 5 specimens, Punta Blanca, Arequipa, Peru, 15°27’37.46”S 75°2’12.24”W, Station1A, coll. from rocky shore at low tide under rocks in water canals,  14 September 2019, by D. Valencia-Sotoand D. Valencia- Valencia, specimens with non-everted pharynges dissected for superficial jaw examination.  MUSMNº 4636, 2 specimens, Punta Blanca, Arequipa, Peru, 15°27’37.46”S 75°2’12.24”W, Station1B, same sampling data and procedure.  MUSMNº 4637, 1 specimen, Punta Blanca, Arequipa, Peru, 15°27’39.36”S 75°2’2.98”W, Station2A, coll. from rocky shore at low tide under rocks,  14 September 2019, by D. Valencia-Sotoand D. Valencia-Valencia, dissected for superficial jaw examination.  MUSMNº 4638, 2 specimens, Punta Blanca, Arequipa, Peru, 15°27’39.36”S 75°2’2.98”W, Station2B, same sampling data and procedure.  MUSMN° 4639 (a), 1 specimen, Punta Blanca, Arequipa, Peru, 15°27’39.36”S 75°2’2.98”W, Station2C, same sampling data and procedure.  MUSMNº 4640, 9 specimens, Punta Blanca, Arequipa, Peru, 15°27’38.70”S 75°2’0.60”W, Station3A, coll. from rocky shore at low tide under rocks,  14 September 2019, by D. Valencia-Sotoand D. Valencia-Valencia, specimens with non-everted pharynges dissected for superficial jaw examination.  MUSMNº 4641, 7 specimens, Punta Blanca, Arequipa, Peru, 15°27’38.70”S 75°2’0.60”W, Station3C, same sampling data and procedure. Four specimens ( MUSMN° 4639b–d) fixed with absolute ethanol, for molecular studies.   Description. Based on specimen MUSM Nº 4590. Individual 17.9 mmlong (from tip of median antennae to tip of anal cirri) and 4.9 mmwide with chaetae ( 4.3 mmwithout chaetae). Body with 26 segments, short, flattened dorsoventrally, rectangular in cross-section ( Fig. 3A–B). Prostomium rounded, bilobed, as long as wide, with three antennae placed antero-terminally ( Fig. 3C). Median ceratophore stout, placed in anterior notch of the prostomium and lateral ceratophores slightly thinner, as anterior projections of the prostomium ( Fig. 3C). Ceratostyles of all antennae with subdistal swellings and filiform tips: lateral ceratostyles shorter than median ceratostyle. Brownish pigmented bands present at base of all ceratostyles and median ceratophore. Two pairs of dark eyes placed dorsolaterally: anterior pair slightly anterior to widest part of prostomium and posterior pair on posterior part of prostomium ( Fig. 3C). One pair of stout, conical, smooth palps with abrupt, tapering tips ( Fig. 3C) and narrow dark pigmented bands along 2/3 of their length. Facial tubercle rounded, with faint dark pigmentation. Tentaculophores lateral to prostomium, cylindrical with one chaeta each. Tentacular cirri with same appearance as median ceratostyle: with subdistal swelling, filiform tips and dark-pigmented bases. Dorsal and ventral tentacular cirri of similar length. Buccal segment with pair of rounded, nuchal nodules; nuchal fold absent ( Fig. 3C). Buccal cirri with same appearance of antennae and tentacular cirri but unpigmented. Dorsal cirri with similar appearance of antennae and tentacular cirri, with remnants of pigmented bands ( Fig. 3A–B). Dorsal tubercles nodular ( Fig. 3B). Parapodia with small, somewhat conical notopodia placed anteriorly ( Fig. 4A–C), with indistinct chaetal lobes. Well-developed neuropodia not deeply incised dorsally and ventrally; prechaetal lobe with subtriangular acicular lobe and postchaetal lobe slightly shorter, distally subtriangular. Neuropodial supra-acicular process and terminal papilla absent ( Fig. 4A–C). Both rami with aciculae penetrating epidermis ( Fig. 4A–C). Ventral cirri long in anterior parapodia and shorter in parapodia of the median region of the body, with bulbous bases, filiform tips and smooth surfaces ( Fig. 4A–C). Nephridial papillae present from 7 thsegment, with blunt ends. Notochaetae arranged in short bundles, with numerous transverse rows of spines: blunt-tipped notochaetae ( Fig. 4D), in superior and middle positions and capillary notochaetae ( Fig. 4E), in inferior position. Notochaetae become longer from superior to inferior positions. Neurochaetae stouter than notochaetae, falcate, subdistally thickened, with subdistal rows of spines; rows of spines larger distally than basally. Second parapodium with superior, long, bidentate neurochaetae ( Fig. 4F) and inferior, shorter, entire-tipped neurochaetae ( Fig. 4G); third parapodium with long superior, and shorter inferior, bidentate neurochaetae ( Fig. 4H–I); parapodia from the middle part of the body with superior, long bidentate neurochaetae ( Fig. 4J) and inferior, shorter entire-tipped neurochaetae ( Fig. 4K). Pygidium with two anal cirri ( Fig. 3B). Twelve pairs of elytra on segments 2, 4, 5, 7, alternating to 23; usually covering all the body, leaving neurochaetae and dorsal cirri exposed. Last three segments non-elytrigerous, covered by last pair of elytra. First pair of elytra slightly rounded ( Fig. 6A), second and third pairs, reniform ( Fig. 6B–C) and remaining elytra, ovoid ( Fig. 7A–B), except for last pair which are slightly triangular ( Fig. 7C). All elytra brown with white margins, a characteristic white S-shaped spot ( Figs 3, 6) and marginal fringe of papillae arranged on AI and AIII ( Figs 6, 7). Elytrophore scars oval to reniform ( Fig. 6, 7). All elytral surfaces are covered by rounded translucent papillae (seen from above) ( Fig. 5B, E, F) and three kinds of hard-walled microtubercles with rounded/oval bases and internal concavities: (a) conical microtubercles with slightly bifid, wrinkled tips (somewhat quadrangular when seen from above) ( Fig. 5A, B, G) mainly on AI, some on margin of AII and AIII ( Figs 6, 7); (b) truncate microtubercles ( Fig. 5C, H) mainly on AI and AII, some on AIII and margin of AIV ( Figs 6, 7) and (c) flattened, hemispherical microtubercles ( Fig. 5D, E, I) mainly on AIII and AIV, some on AI and AII ( Figs 6, 7). Microtubercle morphology changes gradually depending on location, giving rise to transitional forms between zones where each tubercle typepredominates (i.e conical tubercles with truncate, wrinkled tips; flattened, slightly wrinkled tubercles and flattened, slightly truncate tubercles). Like shape, dimensions of microtubercles change gradually over elytral surface depending on location. Except for first pair of elytra, tubercles located on AI and AIII are taller than those present on AII and AIV while tubercle bases are wider when located at AIII, AIV and part of AI. Both height and width of all microtubercle kinds decrease gradually from anterior to posterior pairs of elytra. Size of rounded translucent papillae remain unchanged regardless of location, being the smallest elytral ornamentation. Pharynx with nine pairs of anterior terminal papillae ( Fig. 8A). Two pairs of reddish, chitinous, hollow and asymmetric jaws ( Fig. 8B–C), posterior to papillae. Longer fangs present in dorsal right jaw and ventral left jaw ( Fig. 8B–C). Denticles absent from jaws ( Fig. 8).  Variation.Collected individuals have 26 body segments and range between 7.6–23.4 mmlong and 1.9–6.8 mmwide (including chaetae). Of the 34 examined specimens, 13 were ovigerous. Minimum size for ovigerous specimens was 12.1 mmlong; however, longer non-ovigerous individuals were observed. Significant morphological differences between non-ovigerous and ovigerous specimens were not observed Specimens exhibit a few morphological variations: (1) intensity of elytral colour (usually anterior pairs are darker than posterior pairs); (2) length of the entire-tipped neurochaetae present in the second parapodia (usually these are shorter than the bidentate neurochaetae but some individuals have longer entire-tipped neurochaetae); (3) presence of a small notch near the tips of entire-tipped neurochaetae in the second parapodia (usually absent but few individuals, regardless of their length, exhibit it); (4) flattened, hemispherical microtubercles with nearly polygonal bases on AIV (usually rounded) and narrow —or lacking— internal concavities (see Fig. 5E). None of the variations described above could be correlated to size since these were present regardless of this parameter.   Remarks.The resemblance between collected individuals and  L. crosslandi peruanaHartmann-Schröder, 1962is notable; however, they exhibit a few differences worth mentioning. Specimens differ from the nominal species mainly by the presence of bidentate-tipped neurochaetae in third parapodia, and jaws without denticles. Lack of denticles is persistent in all specimens examined, including individuals smaller than those examined by Hartmann- Schröder (1962a). Presence of some elytral ornamentations (i.e rounded translucent papillae, conical microtubercles with bifid wrinkled tips and truncate microtubercles) appears to be another difference between the two but due to the fact that elytral ornamentations of  L. crosslandi peruanaHartmann-Schröder, 1962were not originally described in detail (see Hartman 1939; Hartmann-Schröder 1962a), it would be necessary to examine the typespecimen of  L. crosslandi peruanaHartmann-Schröder, 1962for an adequate assessment.   FIGURE 3.  Lepidonotusaff. crosslandi peruanaHartmann-Schröder, 1962. A) Dorsal view of the body with elytra (specimen MUSM Nº 4591a); B) Dorsal view of the body, without elytra (specimen MUSM Nº 4590); C) Anterior region of specimen MUSM Nº 4590. Scale bars: A–B) 5mm; C) 1 mm.   FIGURE 4. Parapodia, notochaetae and neurochaetae of  Lepidonotusaff. crosslandi peruanaHartmann-Schröder, 1962 (specimen MUSM Nº 4590). A) 2 ndleft parapodium; B) 3 rdleft parapodium; C) 13 thleft parapodium; D) Superior notochaeta; E) Inferior notochaeta; F) Superior neurochaeta from the 2 ndleft parapodium; G) Inferior neurochaeta from the 2 ndleft parapodium; H) Superior neurochaeta from the 3 rdleft parapodium; I) Inferior neurochaeta from the 3 rdleft parapodium; J) Superior neurochaeta from the 13 thleft parapodium; K) Inferior neurochaeta from the 13 thleft parapodium. Scale bars: A–C) 1 mm; D–K) 20 µm.   FIGURE 5.Elytral ornamentations of  Lepidonotusaff. crosslandi peruanaHartmann-Schröder, 1962 (specimen MUSM Nº 4590). A) Conical microtubercles with bifid, wrinkled tips (seen from above) from AI; B) Same, details of the tips; C) Truncate microtubercles from AII; D) Flattened, hemispherical microtubercles from AIV; E) Variation of the former, without internal canals. Illustration of each ornamentation type and designation of symbols. F) Translucent rounded papillae as tiny black circles; G) Conical microtubercles with bifid, wrinkled tips as red circles; H) Truncate microtubercles as green circles; I) Flattened, hemispherical microtubercles as yellow circles. Scale bars: 40 µm. Abbreviations: pp, translucent rounded papillae; bwt, micro- tubercles with bifid, wrinkled tips.   FIGURE 6. Anterior elytra of  Lepidonotusaff. crosslandi peruanaHartmann-Schröder, 1962 (specimen MUSM Nº 4590) with their respective illustration of ornamentation distribution. A) 1 stright elytron; B) 2 ndright elytron; C) 3 rdright elytron. Scale bars: A–C) 1 mm.   FIGURE 7. Posterior elytra of  Lepidonotusaff. crosslandi peruanaHartmann-Schröder, 1962 (specimen MUSM Nº 4590) with their respective illustration of ornamentation distribution. A) 10 thright elytron; B) 11 thright elytron; C) 12 thright elytron. Scale bars: A–C) 1 mm.   TABLE 3. Comparison between  Lepidonotusaff. crosslandi peruanaHartmann-Schröder, 1962 and other  Lepidonotusspeciesdescribed for the Pacific Coast of South America. Data from descriptions based on type and additional material. Some descriptions were translated to English language.    Species Nuchal projec- tions Elytral colour Elytral ornamenta- tions Marginal papil- lae Notochaetae Neurochaetae Jaws References    Lepidonotuscross- landi Monro, 1928 According to Monro (1928): “there is a distinct nuchal fold”. According to Monro (1928): Two speci- mens with elytra “cream-coloured with a small black patch over the elytrophore and a number of paler round dots” and one individual with “dark grey scales with a light patch over the elytro- phore. (…) Pigment is arranged in alveolar patches”. According to Monro (1928): “Elytra thinly dot- ted with small prominences”. According to Monro (1928): “Elytra are sparsely fringed on the extero- lateral border”. According to Monro (1928): “Extremely fine (…) resemble those figured for  L. tenuisetosus(Gravier)”. Spinous sub- distally. Biden- tate in the 2nd parapodium and entire-tipped in remaining para- podia (see Monro 1928). Not described (see Monro 1928).  Monro (1928)    Lepidonotus savignyi(Grube & Kröyer in Grube, 1857) Not described (see Augener 1925) Not described (see Augener 1925) Elytra with conical papillae. Bidentate conical papillae in front of the posterior margin of the elytron (see Augener 1925). Present at the rear edge of the elytra (see Auge- ner 1925). Spinous notocha- etae of two kinds: Short-tipped and hair-like with slender tips (see Augener 1925). Bidentate neu- rochaetae (see Augener 1925). Not described (see Augener 1925).  Augener (1925)  “Papillae” could mean “tubercles”.  ......continued on the next page  TABLE 3. (Continued)    Species Nuchal projec- Elytral colour Elytral ornamenta- Marginal papil- Notochaetae Neurochaetae Jaws References  tions tions lae    Lepidonotuscross- According According to Hartman According to Hart- According to Superior notocha- Bidentate and en- Two reddish- Hartman   landi peruanaHart- to Hartman (1939): “(Elytra) have man (1939): “Nu-  Hartman (1939): etae with blunt tire tips (second, brown pairs (1939),  mann-Schröder, (1939): a characteristic broad, merous trim, small “(Elytra) sparse- tips, smaller than thrid and median of jaws with Hartmann-  1962. “Anterior edge dusky crescent around flattened tubercles, ly fringed on the inferior notocha- parapodia) (see fine denticles Schröder  of the sec- the posterior half of approximately of outer, postlateral etae (see Hart-  Hartman (1939)). (Hartmann- (1962a)  ond segment elytral scar which two sizes”. edge”. mann-Schröder Schröder  projects gradually fades out at (1962a)) (1962a))  forward (…) the posterior margin”.  in the form of  a pair of short  flaps.”     Lepidonotusaff. Nuchal nod- With a characteristic Four kinds of Present Two kinds of Spinous subdis- Reddish, The present    crosslandipe- ules present. white S-shaped dot on ornamentations: (1) spinous notocha- tally. without den- study.    ruanaHartmann- a brown background rounded papillae, etae: (1) blunt- Second para- ticles.   Schröder, 1962. and white margins. (2) conical mi- tipped, on superior podium with  crotubercles with position and (2) bidentate and  bifid, wrinkled tips, capillary, on infe- entire-tipped  (3) truncate micro- rior position. neurochaetae;  tubercles and (4) third, bidentate  flattened microtu- and median  bercles. parapodium with  bidentate and  entire-tipped  neurochaetae.  ......continued on the next page ......continued on the next page  TABLE 3. (Continued)    Species Nuchal projec- Elytral colour Elytral ornamenta- Marginal papil- Notochaetae Neurochaetae Jaws References  tions tions lae    Lepidonotusareno- From images, Mostly monochrome Thick egg- or pear- Elytra fringed Thin bristles with Bristles cov- Not described Ehlers   susEhlers, 1901. an inconspi- with a small subcentral shaped papillae on with long short notches to ered with short (see Ehlers (1901a,  cous nuchal dark areolated spot and the surface (Ehlers filiform papillae the tip (see Ehlers teeth for a short 1901b). 1901b).  fold (see Eh- scattered black dots 1901a). on the outer 1901b). distance in front  lers 1901b). (see Ehlers 1901b). edge (see Ehlers of the bidentate  Papillae like small 1901b). Perhaps, by “short tip (see Ehlers  granules; towards notches” Ehlers 1901b).  the fringed and referred to spinous  posterior margin surfaces.  become larger tear-  drop-shaped, hard,  more refractive  (see Ehlers 1901b).    Lepidonotusfurcil- Second seg- Yellow-gray surface Small, rounded- Some of the Bristles much A bristle carries Not described Ehlers   latusEhlers, 1901 ment with with a lighter or darker, nodular papillae elytral edges thinner than those 6-9 comb- (see Ehlers (1901a,  anterior two- subcentral spot (see and large, hard, are fringed with of the lower toothed trans- 1901b). 1901b).  pronged lobe  Ehlers 1901b). curved conical thin threads (see branch, spinous versal blades  (see Ehlers papillae, which  Ehlers 1901b). almost to the in front of the  1901b). unevenly taper to a pointy end (see bidentate end tip  simple point or are  Ehlers 1901b). for a short dis-  irregularly split at tance (see Ehlers  the tip (see Ehlers 1901b).  1901a, 1901b).  TABLE 3. (Continued)    Species Nuchal projec- Elytral colour Elytral ornamenta- Marginal papil- Notochaetae Neurochaetae Jaws References  tions tions lae    Lepidonotusmar- Not described Not described (see Elytra smooth. Elytra are cili- Few, very thin, Yellow, short With worn Kinberg   garitaceusKinberg, (see Seidler  Seidler 1923). Outer edge of the ated on the edge linear sawn bris- bristles thickened tooth and (1856),  1856 1923). elytra slightly ( Kinberg 1856; tles (see Seidler and serrated short point Quatrefages  granulated (see Quatrefages 1923). below the short, (see Seidler (1866), Sei-   Seidler 1923). 1866). Tightly slightly curved 1923). dler (1923).  fringed on the tip (see Seidler  outer and rear 1923).  edges (see  Seidler 1923).    Lepidonotus According to According to Cham- According to According to According to Spinous neu- Not described Chamberlin   nesophilusCham- Chamberlin berlin (1919): “Color Chamberlin Chamberlin Chamberlin rochaetae. (see Cham- (1919)  berlin, 1919 (1919): “A pair of the elytra is greyish (1919): “Tubercles (1919): “Along (1919): “Noto- Bidentate in berlin 1919).  of low dorsal green, paler toward the vary from hemi- the ectocaudal podial setae are anterior somites  tubercles occur ectal side; a larger light spherical to forms edge of the either straight or, and entire-tipped  on the somite spot is over the point constricted at the elytron, there is more typically, in posterior seg-  I”. of attachment and nu- base and so more a series of short curved (…). Each ments (  Chambermerous small light dots nearly spherical. and slender seta appears in lin 1919).  about this”. The tubercles are transparent rods surface view  densely spinescent, projecting freely bipinnate, there  the spines being from the edge”. appearing a fringe  proportionately of close-set  translonger and coarser parent fine teeth  on the smaller along each side”.  tubercles”.   FIGURE 8. Pharynx and jaws of  Lepidonotusaff. crosslandi peruanaHartmann-Schröder, 1962. A) Frontal view of pharynx. B) Dorsal jaws seen from the pharyngeal lumen. C) Ventral jaws seen from the pharyngeal lumen. Scale bars: A) 1 mm; B–C) 400 µm. Until such time as this is possible, individuals are here considered as a “toothless” variation of  L. crosslandi peruanaHartmann-Schröder, 1962. Comparison between  Lepidonotusaff. crosslandi peruanaHartmann-Schröder, 1962 and other  Lepidonotusspeciesrecorded for the Pacific Coast of South America can be found in Table 3.   Distribution.  Lepidonotusaff. crosslandi peruanaHartmann-Schröder, 1962 is here recorded for Punta Blanca ( Arequipa, Peru).  Lepidonotus crosslandi peruanaHartmann-Schröder, 1962has previously been recorded from Callao( typelocality), Independencia Bay ( Hartman 1939, as  Lepidonotus crosslandiMonro), Cañete ( Tasso et al.2018), Lima( Paredes et al.1999) and Pisco ( Paredes et al.1988), Peru.   Ecology.Found along with individuals of  Harmothoeaff. hirsuta Johnson, 1897(described below). As far as was observed, specimens of both species did not exhibit aggressive behaviours to each other. 2019-09-14 MUSM Station & D. Valencia-Soto & D. Valencia-Valencia Peru -15.46075 Punta Blanca 1 -75.0335 Arequipa 4 155 1 MUSM Peru 4 155 6 2019-09-14 MUSM Station & D. Valencia-Soto & Valencia Peru -15.460405 Punta Blanca 1 -75.036736 4 155 5 Arequipa MUSM Station Peru -15.460405 Punta Blanca 1 -75.036736 4 155 2 Arequipa 2019-09-14 MUSM Station & D. Valencia-Soto & D. Valencia-Valencia Peru -15.460933 Punta Blanca 1 -75.03416 4 155 1 Arequipa MUSM Station Peru -15.460933 Punta Blanca 1 -75.03416 4 155 2 Arequipa MUSM Station Peru -15.460933 Punta Blanca 1 -75.03416 4 155 1 Arequipa 2019-09-14 MUSM Station & D. Valencia-Soto & D. Valencia-Valencia Peru -15.46075 Punta Blanca 1 -75.0335 4 155 9 Arequipa MUSM Station Peru -15.46075 Punta Blanca 1 -75.0335 4 155 7 Arequipa