Pilargis, de Saint-Joseph, 1899

Salazar-Vallejo, Sergio I. & Harris, Leslie H., 2006, Revision of Pilargis de Saint-Joseph, 1899 (Annelida, Polychaeta, Pilargidae), Journal of Natural History 40 (3 - 4), pp. 119-159 : 126-132

publication ID	https://doi.org/ 10.1080/00222930600594212
persistent identifier	https://treatment.plazi.org/id/039487A1-B45D-FFCB-F6F4-FB1CFC37FDF2
treatment provided by	Carolina
scientific name	Pilargis
status

Treatment

Pilargis View in CoL IJerrucosa de Saint-Joseph, 1899

( Figures 1–3 View Figure 1 View Figure 2 View Figure 3 )

Pilargis View in CoL υerrucosa de Saint-Joseph 1899a, p 42, 1899b, p 175–180, Plate 6, Figures 10 View Figure 10 –17; Fauvel 1920, p 206–208, 212–213, Figure 1 View Figure 1 a–e; Charrier 1924, p 1–7, Figures 1–11 View Figure 1 View Figure 2 View Figure 3 View Figure 4 View Figure 5 View Figure 6 View Figure 7 View Figure 8 View Figure 9 View Figure 10 View Figure 11 ; Fauvel 1925, p 88–90.

Pilargis View in CoL sp. Harmelin 1964, p 72, Plate 1, Figures 1–4 View Figure 1 View Figure 2 View Figure 3 View Figure 4 .

Type material

Northeastern Atlantic Ocean: syntype ( MNHN-A 278fA) of Pilargis υerrucosa de Saint- Joseph, 1899, coll. de Saint-Joseph, Brest (tags: collection number 20, 1911; ‘‘ Pilargis verrucosa exemplaire femelle entier partie anterieur en 3 trançons prés 5 segments … Brest … 1898’’). Syntype ( MNHN-A 278fP) of Pilargis υerrucosa de Saint-Joseph, 1899, coll. de Saint-Joseph, Brest, 1 April 1898 (tags: one like above, other with: ‘‘ Pilargis verrucosa exemplaire femelle … partie posterieur en 2 trançons, partie anterieur en 3 trançons, en 2 verres … Brest’’). Syntype ( MNHN-A 278m), same data as above (tag: ‘‘ Pilargis verrucosa exemplaire male incomplet en 2 tronçons, il manque un cirre tentaculair pres 121 ou 140 segment pour … Brest 1er Avril 1898 ’’).

Additional materials

Complete specimen fixed in alcohol ( MNHN-A 71), colorless, bad condition, coll. M. Blanchard, no locality, id. P. Fauvel (pharynx everted, globose almost smooth, with some longitudinal thin striae, as long as the first three setigers). Complete specimen (MNHN- A437), coll. Cuénot, Arcachon, id. as Pilargis υerrucosa (5 P. perezi Charrier), legit Fauvel (very well preserved, gray, anterior end slightly compressed, posterior end in regeneration; 86 mm long, 4.5 mm wide, 138 setigers. Regenerating posterior end 8 mm long, 2 mm wide, 28 setigers, 15 asetigers), who used it for the redescription ( Fauvel, 1920). Posterior fragment ( MNHN-A 409), coiled (82 mm long, 2.6 mm wide, 144 setigers, posterior end regenerating, 26 setigers, two to three asetigers, and pygidial bulb. This has a smooth basal section, distal rounded portion and ventrolateral anal cirri covered by verrucae). Median fragment ( MNHN-A 491) idem (ca. 50 mm long, 3.5 mm wide, ca. 180 setigers; dark gray, slightly dehyrated. Three parapodia removed; neurosetae partly broken or covered with adsorbed material, tip slightly curved bidentate). One complete, splendid male ( MNHN-A 494), id. as P. υerrucosa, Ourse de Kersos, Concarneau, 11 June 1965 (160 mm long, 3.5 mm wide, ca. 300 setigers, 210 setigers and posterior section with ca. 90 setigers; posterior end with two to three asetigers, a smooth tapering anal plate, two ventrolateral anal cirri, abundant large verrucae, especially dorsally. Anal cirri 10 times longer than anal verrucae). Mediterranean Sea: One complete juvenile and a small specimen regenerating the posterior end ( ECOSUR), coll. F. Pleijel and A. Mackie, Cap Oullestrel, Banyuls-sur-mer, 7 October 1991, muddy bottoms, 40 m, legit F. Pleijel. One complete juvenile (SMF-11214/1), coll. Meteor 25th cruise, Levantin Basin, Stat. 35KG1.

Redescription

Since the original description and Fauvel’s redescription are good, a few comments will be added on the type material.

Female syntype (A278fA). Three fragments, pale, anterior one 12 mm long, 3.5 mm wide, 39 setigers; median large portion 10 mm long, 3.2 mm wide, 27 setigers; short median portion 3 mm long, 3 mm wide, four setigers. First dorsal cirri larger than the one of setiger 2 ( Figure 1A View Figure 1 ); dorsal cirri much larger than ventral one, 1.5–2.0 times longer and 2–5 times wider, can be separated in cirrophore and cirrostyles, about equal-sized but cirrophore much wider ( Figure 1C, D View Figure 1 ). No posterior end available; larger verrucae conical or mammiliform, those present on dorsal cirrostyles, ventral cirri, and ventral surface low cylindrical; once cleaned, none has any filament through the transparent integument, as was depicted in the original Figure 17. Bifid setae could not be confirmed because of the amount of adsorpted salt over them; this has already been noticed by Fauvel (1925, p 90).

Female syntype (A278fP). Two fragments, both pale, one median 18 mm long, 3.6 mm wide, 38 setigers, a posterior larger fragment 62 mm long, 3.5 mm wide, 102 setigers. Posterior end (examined using methyl green staining) without anal cirri ( Figure 1B View Figure 1 ); correctly described as lacking anal cirri. Eggs large, about 240 mm.

Male syntype (A 278m). Two fragments, pale, anterior one 44 mm long, 4 mm wide, 124 setigers; median portion 18 mm long, 4 mm wide, 18 setigers. Both partly dehydrated, show a deep ventral furrow, stiff; anterior fragment previously dissected ventro-longitudinally, from slightly after the mouth to setiger 42, but blade went through both body walls, several parapodia removed. Some neurosetae free of adsorbed materials, smooth limbate capillaries distally curved, a main and an accessory tooth. The difference that de Saint- Joseph noticed between male and female was probably due to the different degree of dehydration, which changes the general body appearance and the relative proportions of the parapodia . Larger verrucae over middorsal and parapodial base areas, though the whole dorsum is covered by verrucae. Sperm abundant in coelom, head globose, about 3 mm long.

Juυeniles. Complete specimen ( ECOSUR), 9.5 mm long, 0.4 mm wide, without any median expansion, 52 setigers, four asetigers. Integument with sparse verrucae, except in the anterior end. Body with a series of glandular masses dorsally and ventrally in parapodial bases, in setigers 3–35 about the same size, pigmentation fading towards setiger 30, disappear in setiger 35, reappear only in setiger 43; they disappear in the posterior region, although there is a dark lateral gland in the pygidial bulb.

Prostomium with biarticulated palps, palpostyles central directed forward; lateral antennae inserted on the base of the palps, slightly pass prostomial margin but not palp tips ( Figure 2A View Figure 2 ). Tentacular segment projected forwards; tentacular cirri with verrucae, dorsal one slightly larger than ventral one. First setiger with dorsal cirri larger than dorsal tentacular cirri and dorsal cirri on setiger 2. Ventral cirri longer than setal lobe. Parapodia with acuminate cirri, dorsal cirri larger than ventral one, both larger than setal lobe.

Posterior end with four asetigers, pygidial bulb with abundant verrucae, from its medial portion towards the posterior margin, two ventrolateral cirri, over 10 times the size of adjacent verrucae ( Figure 2B View Figure 2 ). Most verrucae over anterior end and over parapodial cirri are not flat; rather bifid or trifid, tend to be regularly placed over the body; three ones over lateral margins of tentacular segment, two to three over dorsal cirrostyles and one subdistal in ventral cirri ( Figure 2A View Figure 2 , insert). Brain elongated, posteriorly bilobed, reaches about the middle of second setiger. Gut straight; lateral diverticula not seen.

Another juvenile ( SMF) completely transparent ( Figure 2C, D View Figure 2 ); two large dorsal ovoid dark gland masses from setiger 3, and two other ones over the ventral surface, continue towards some five setigers before pygidium, giving the specimen a distinct spotted regular pattern. Tentacular cirri directed anterolaterally, first dorsal cirri about the same size as second setiger ones. Posterior end with two asetigers, short pygidial bulb, two lateral anal cirri, all with large verrucae. Gut diverticula from setiger 1.

Variability

The insertion of the lateral antennae, as well as size relationships between anterior end cirri, are consistent since they become fixed in small specimens. However, the abundance and shape of verrucae differ from larger specimens; dorsal verrucae shape differs, and those present over cirri tend to be smaller in larger specimens. A comparison of parapodial development in different organisms is shown in Figure 3 View Figure 3 ; cirri are always more or less globose, blunt, and dorsal larger than ventral ones. Dorsal verrucae are always larger ( Figure 3 View Figure 3 B–F), inverted cone- or dune-shaped ( Figure 3E View Figure 3 , insert), than those placed over the cirrostyles; these are often distally expanded ( Figure 3F View Figure 3 , insert), and arranged in a single longitudinal line over the cirrostyles.

The dark glandular material is present just before the dorsal cirrophore ( Figure 2A, C View Figure 2 ) and disappears in larger specimens; first appearing as small globular structures and later they cannot be seen again. Likewise, body outline changes a lot since the juvenile is almost cylindrical or slightly tapered towards both ends, while the adult is markedly wider in the median region than towards any end. The posterior end is rather variable although the basic structure is more or less retained, the anal cirri might regenerate and the swelling of the pygidial bulb ( Figure 3A View Figure 3 ) may change with contraction. Gut diverticula are seen in every setiger in juveniles ( Figure 2C View Figure 2 ) and continue to the last prepygidial setiger ( Figure 2D View Figure 2 ).

Fauvel incorrectly stated that verrucae are restricted to the dorsal side of dorsal cirri, since they are present, though smaller, over the ventral parapodia surface. Anterior end lacks the caruncle that Fauvel had noticed; it has a rather smooth surface without large verrucae. Further, the posterior brain lobes are slightly darker, placed inside setiger 1, and somewhat fusiform pointing anterolaterally. Posterior end as a pygidial bulb heavily covered by large truncate verrucae, but may lack anal cirri; neurosetae masked by adsorpted materials but a few of them show an almost smooth limbus and a distally curved bifid tip, as was illustrated for it.

Discussion

Pilargis View in CoL υerrucosa has no sexual dimorphism, as has been already stated by Katzmann et al. (1974, p 21); however, it includes two different morphs in the Bay of Biscay, depending on the abundance and size of verrucae: the typical morph has abundant large verrucae over the back and parapodia View in CoL , and the atypical morph has few and smaller verrucae. There are other differences in the anterior end and parapodial cirri; however, since sampling depth was not recorded, this variation remains unexplained. Therefore, those morphs with few verrucae are herein regarded as members of P. modesta Intes and le Loeuff, 1975 View in CoL , which is a southern species; it seems that these latter authors did not include the paper by Katzmann et al. (1974) because it was in press.

Distribution

France, Iberian Peninsula and Mediterranean Sea, in 2–300 m depth .