Grania bekkouchei Prantoni & Wit & Erséus 2016, SP. NOV
Creators: name: Prantoni, Alessandro Lívio
name: Wit, Pierre De
name: Erséus, Christer
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Clitellata
Enchytraeida
Enchytraeidae
Grania
Grania bekkouchei

description: GRANIA BEKKOUCHEI SP. NOV.  FIGURE 2  
 Holotype   
 SAMC A82466, CE13996, whole-mounted, sexually mature specimen, ten posterior segments amputated, from Saldanha Bay, West Coast district, Province of the Western Cape, South Africa, 33°00′25″S, 17°56′45″E, intertidal coarse sand in rock crevice. Collected by N. Bekkouche, 13 December 2011. COI barcode sequence, GenBank acc. no. KT428107; for other sequence data, see Table 1.   
 Etymology   
Named for Nicolas Bekkouche, the collector of the type material.  
 Paratypes   
 Six whole-mounted, sexually mature specimens, all collected by N. Bekkouche. SAMC A82467, CE13975, with 13 posterior segments amputated; SAMC A82468, CE13995, with some segments amputated, SAMC A82469, CE13997, with 11 middle body segments amputated; SAMC A82470, CE13998, with nine middle body segments amputated; all from the type locality and the type date. SAMC A82471, CE14035, with some segments amputated, from Glencairn Heights, False Bay, City of Cape Town, Province of the Western Cape, South Africa, 34°09′29″S, 18°26′01″E, lower intertidal rocky pool, 15 December 2011. SAMC A82472, CE14059, with seven middle body segments amputat- ed from Van Dyks Bay, Overberg District, Overstrand Local Municipality, Province of the Western Cape, South Africa, 34°37′00″S, 19°21′21″E, rocky beach, shallow subtidal, 16 December 2011. For COI barcodes of paratypes, see Table 1.   
 Description   
 Body> 6.6–12.5 mm long (n = 5), comprising 55–72 segments (n = 5) (including the segments used for DNA analysis), 0.16–0.17 mm wide at segment III, and 0.15– 0.23 mm wide at segment XII (n = 7). Prostomium rounded, 50–77 μm long, 55–80 μm wide, occasionally epidermis slightly reduced at front tip, 7–12 μm thick (n = 7). Ventral chaetae from segment IV, lateral chaetae from segment XIV (n = 4) or segment XV (n = 3), sometimes present in preclitellar segments VII–VIII (n = 1), VII–IX (n = 1), or VII–X (n = 1). Chaetae (Fig. 2A) 54–74 μm long, shaft straight, 3.7–6.2 μm thick at midpoint, L-shaped, proximally bent into a foot with broad instep and indistinct heel. Chaetal index (Rota & Erséus, 2003) 4.92 ± 0.68 (n = 5). Free chaetae (partly resorbed?) scattered in coelomic cavity, mostly in preclitellar segments. Epidermal gland cells inconspicuous. Clitellum 12–19 μm thick, extending from segment XII to middle of segment XIII, formed by more or less regular transverse rows of granular cells, absent between male pores, hyaline cells not observed. Spermathecal pores in lateral lines, at short distance from 4/5. Male pores ventrolateral in mid segment XII. Female pores lateral (?) in 12/13.   
 Brain posteriorly indented. Head organ (sensu Rota & Erséus, 1996) absent. Pharyngeal glands in segments IV–VI; dorsal lobes present in segments IV (one pair), V (one pair), and VI (one pair), ventral lobes present in segments IV (one pair), V (two pairs), and VI (two pairs); glands not connected dorsally. Nephridia not observed. Chloragogen cells inconspicuous. Dorsal blood vessel commencing in segments XVIII–XX. Coelomocytes not observed. Sperm sac reaching XVII. Egg sac extending into segments XVII–XXII. Sperm funnels about 2.5 times longer than wide (n = 5; Fig. 2C). Vasa deferentia 7.5 μm wide, internally ciliated, coiled, extending into segments XII–XV. Penial apparatus type 1 (sensu Coates, 1984), with oval or round bulb, 55– 77 μm long, 45–87 μm wide (n = 7); bulb glandular, surrounding a simple invaginated male pore; stylet absent (Fig. 2C). Midventral copulatory gland (in segment XIV) present. Spermathecae communicating with oesophagus at posterior end of segment V. Ectal duct of spermatheca 75–110 μm long, 27–43 μm wide, muscular, maintaining uniform width over its entire length, proximally curved to enter ampulla, devoid of glands at pore. Spermathecal ampulla 60–75 μm long, 60– 82 μm wide, dome-shaped with granular walls, containing sperm rings, each maximally 15 μm wide (Fig. 2B).   
 Remarks   
 Although noted for some unidentified specimens from the Marion and Crozet islands in the Southern Indian Ocean (see Rota & Erséus, 1997), the presence of lateral chaetae in preclitellar segments is rather unusual in this genus, and is only formally reported for G. lasserrei and one specimen of G. monochaeta, both from South Georgia Island (Rota & Erséus, 1997). According to Erséus & Lasserre (1976) and Rota & Erséus (1997), the beginning of the chaetal distribution, particularly that of the lateral chaetae, is subject to considerable intraspecific variation. Even so, G. lasserrei differs from G. bekkouchei sp. nov. by its spermatheca, which has a dorsal, thin-walled, and sacciform diverticulum on the spermathecal ampulla. In G. monochaeta the ectal duct of the spermatheca narrows at both ends. The ampulla of G. bekkouchei sp. nov. is dome-shaped and the ectal duct maintains the same width along its entire length. In addition, G. lasserrei possesses a head organ, which is absent in G. bekkouchei sp. nov.   
Although seldom noted in descriptions of Enchytraeidae, we observed a lateral ring of histologically distinct cells indicating a small pore-like structure in the intersegmental furrows 12/13 of the holotype: we interpret these structures as the female pores.  
 Among the new South African species described here, G. bekkouchei sp. nov., and its cryptic sister species Grania cryptica sp. nov., differ from Grania capensis sp. nov. in the morphology of the spermathecae. Unlike the former two species, G. capensis sp. nov. has a pear-shaped ampulla and an ectal duct that narrows near the pores. The species are also separated by the chaetal distribution, although some anterior lateral chaetae are irregularly distributed in all three (see the preceding paragraph). The postclitellar lateral chaetae start in segments XIV–XV in G. bekkouchei sp. nov., in segment XVIII in G. cryptica sp. nov., and in segments XXI–XXII in G. capensis sp. nov. In addition, the chaetae of G. bekkouchei sp. nov. have a broad instep and no prominent heel, which make them morphologically different from those of G. capensis sp. nov. (see Figs 3, 5).   
 Grania simonae sp. nov., also from South Africa, is easily distinguished from G. bekkouchei sp. nov. by the absence of lateral chaetae, the absence of a midventral copulatory gland (in segment XIV), the morphology of the spermathecae, and the start of the dorsal blood vessel (see remarks for G. simonae sp. nov. below).   
 A cryptic form, morphologically similar to G. bekkouchei sp. nov., is described as a separate species below (G. cryptica sp. nov.).
description: Published as part of Prantoni, Alessandro Lívio, Wit, Pierre De & Erséus, Christer, 2016, First reports of Grania (Clitellata: Enchytraeidae) from Africa and South America: molecular phylogeny and descriptions of nine new species, pp. 485-510 in Zoological Journal of the Linnean Society 176 (3) on pages 491-492, DOI: 10.1111/zoj.12333, http://zenodo.org/record/4720622