Grania quaerens, Rota & Wang & Erséus, 2007
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publication ID |
https://doi.org/ 10.1080/00222930701391682 |
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persistent identifier |
https://treatment.plazi.org/id/FA09AD4F-FFFB-FFA3-2B60-50D594AA1D8B |
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treatment provided by |
Felipe |
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scientific name |
Grania quaerens |
| status |
sp. nov. |
Grania quaerens sp. n.
( Figures 5B–D View Figure 5 , 6A–I View Figure 6 )
Type material
Holotype: WAM V 7315 , whole-mounted specimen, fully mature, from north of New Island , 34 ° 0.849S, 122 ° 8.529E, rocky shore, lower intertidal, medium to coarse sand under rocks, 6 February 2003 (Stn ES03-5 A) GoogleMaps . Paratypes: WAM V 7316–7319 , four specimens numbered in this order: three from type locality ( V 7318 missing posterior segments), and one from Stn ES03-28 D. SMNH Type Coll. 6803–6808, six specimens: five from type locality (two missing posterior segments), and one from Stn ES03-36 . MCZR Oligochaeta 0146–0149, four specimens from type locality (one missing posterior segments). All but one specimen fully mature .
Description
Body 5.8–7.2 mm long (n 55), 0.19–0.22 mm wide at V, 0.22–0.26 mm at XII (n 58). Segments of complete adults 49–53 (n 57). Prostomium small, rounded ( Figure 6C, D View Figure 6 ), 62 mm long, widening out bell-wise at 0/1 (80–88 mm) (n 52) to meet twice as broad peristomium; epidermis not notably reduced at front tip (5–8 mm thick). Lateral chaetae from XIV (13 specimens) or XV (two specimens), ventral chaetae from IV. Chaetal shaft straight, 3.2–5.6 mm thick at mid-point, proximally bent into a short, thin, oblique (110–125 ° to the shaft) foot with low instep and receding heel; tip of foot straight ( Figures 5B View Figure 5 , 6B View Figure 6 ). Preclitellar chaetae 35–62 mm long, with foot 7–9.5 mm long; postclitellar chaetae 35–67 mm long, with foot 7–13 mm long. Chaetal index 5.21, n 510, s 50.644. Shaft length and thickness slightly increasing towards posterior body end; shortest and thinnest lateral and ventral chaetae recorded near XX. Epidermal gland cells inconspicuous, except in a poorly preserved specimen from ES03-36 which from XVIII to posterior end shows a complete row of deep-staining, large (6.5–8 × 19–22 mm) rectangular cells per segment at chaetal level. Clitellum ( Figure 6A, E View Figure 6 ) extending over XII and most of XIII, maximally 13–17.5 mm thick, comprising small gland cells arranged in about 35 regular transverse rows; granular type interspersed with hyaline cells except lateral to and, ventrally, posterior to male pores where dense granular fields occur; both types absent midventrally between male pores ( Figure 6E View Figure 6 ). A small ‘‘copulatory gland’’ midventrally in XIV. Spermathecal pores in lateral lines, immediately posterior to 4/5 ( Figure 6G View Figure 6 ) .
Brain indented posteriorly. Head organ absent. Pharyngeal glands at 4/5–6/7, not united dorsally; ventral lobes in IV–VI. Ventral lobes of IV twice as long as dorsal lobes ( Figure 6C View Figure 6 ). Gut contents characterized by large amounts of coarse, thin-walled organic matter, some diatom shells, and spicule fragments. Rectal ampulla short, with trapezoidal sagittal section ( Figure 6H View Figure 6 ). First nephridia at 7/8. Dorsal blood vessel arising in XVIII or XIX. Coelomocytes numerous, small, with irregular oval or round outline, up to 13 mm long; cytoplasm with refractile, fine granulation thinning out around cell nucleus ( Figure 6I View Figure 6 ). Sperm sac extending into XIV–XVI. Sperm funnels four to five times longer than wide (192–200 × 40–48 mm), as long as inner body diameter at clitellum, cylindrical with a short hyaline portion below collar. Heads of sperm 16–18 mm long. Each vas deferens 8–9 mm wide, coiled in tight spirals in XII ( Figure 6F View Figure 6 ), or extending backwards as far as XIV inside sperm sac, showing thin ciliated walls all the way to penial apparatus. Latter comprising an elongated glandular body (125 mm) centred at male pore, which is joined by vas from posterior dorsal aspect, and a long whip-like stylet (V 7318 missing posterior segments) ( Figure 5D View Figure 5 ). Inside penial apparatus, vas thicker (12 mm), muscular and unciliated, forming a stiff curve in the anterior part of glandular body; here vas cells endowed with large nuclei all along enclosed section of stylet ( Figures 5D View Figure 5 , 6F View Figure 6 ). Stylet totally about 210–258 mm long (n 57), diameter constantly 4 mm in initial one-third (located inside vas deferens), then gradually attenuating to 1 mm at distal end; free part of stylet coiled into one and a half perpendicular loops located inside deep male invagination and aglandular sac, but in fixed specimens distal end often protruding through male pore ( Figure 6E View Figure 6 ). Stylets fully developed in subadult specimen. Egg sac extending into XVII–XIX. Spermathecal ducts not notably muscular, 90–100 mm long, ectally bulbous (25 mm thick), 15 mm thick at midcourse, not thinning entally; inner canal maintaining uniform diameter throughout duct’s length, joining ciliated ampullar cavity through conspicuous, short-conical intrusion ( Figures 5C View Figure 5 , 6G View Figure 6 ); ampullae oval, 55–75 mm long, 43–55 mm wide, granulated ectally; 8–12 sperm rings, 7.5–12.5 mm in diameter, embedded in clear ampullar walls of ental portion ( Figures 5C View Figure 5 , 6G View Figure 6 ). No separate glands at ectal pores of spermathecae.
Etymology
The specific name is Latin for ‘‘seeker, searcher’’, in reference to its occurrence in the Recherche Archipelago.
Remarks
Diagnostic for this new species is the combination of a high chaetal index (5 short chaetal foot), small coelomocytes, long penial stylets forming loops inside the deep epidermal invaginations at male pores, conspicuous spermathecae with ectally bulbous ducts, and ectally granulated ampullae housing sperm rings in their ental region. The named features of the spermathecal ampullae (ectal granulation of walls and ental location of sperm rings), as well as the unusual length of the penial stylets, are reminiscent of the Western Australian G. longistyla Coates and Stacey, 1993 and G. ersei . In fact, at first sight one may have the impression that G. quaerens is but a small-sized version of G. ersei , with the shorter reproductive organs (spermathecal ducts and penial stylets are about one-half the length of those of G. ersei ) being simply related to the smaller body size, but this is not so. The body size of G. ersei and G. quaerens largely overlap. Moreover, both G. ersei and G. longistyla have a different chaetal shape from G. quaerens (low chaetal index at least in G. ersei , see above) and lack preclitellar nephridia. Finally, as G. vacivasa , G. quaerens differs from G. ersei and the other species identified in the Esperance area by the lack of the head organ.
Distribution and habitat
South coast of Western Australia (Esperance). Exclusively found in lower intertidal, medium to coarse sand.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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