Agrafia wiktori, Szarowska & Falniowski, 2011

Szarowska, Magdalena & Falniowski, Andrzej, 2011, An unusual, flagellum-bearing hydrobiid snail (Gastropoda: Rissooidea: Hydrobiidae) from Greece, with descriptions of a new genus and a new species, Journal of Natural History 45 (35 - 36), pp. 2231-2246 : 2235-2240

Agrafia wiktori sp. nov.

( Figures 2–5 )

Material examined

Holotype. Greece, Evrytania , Agrafa Mountains, 774 m, 39 ◦ 22 ′ 07 ′′ N, 21 ◦ 37 ′ 53 ′′ E, Sikiá, 20 June 2007, leg. Szarowska and Falniowski (sieve), ethanol-preserved, in collection of Zoological Museum of Jagiellonian University (ZMJU-M-0007-1105): 41 / 4 SWN, 1.60 mm TSL, 0.56 mm SSL, 0.65 mm SML, 1.02 mm TSW, 0.87 mm BWW, 0.64 mm SMW.

Paratypes. Two specimens, same site and date of collection, ethanol-preserved, vial deposited at Zoological Museum of Jagiellonian University (ZMJU-M-0007-1106). 41 / 4 to 41 / 2 SWN, 1.56–1.82 mm (mean ± SD, 1.66 ± 0.101) TSL, 0.46–0.68 mm (0.52 ± 0.057) SSL , 0.64–0.72 mm (0.67 ± 0.039) SML, 1.00– 1.06 mm (1.03 ± 0.025) TSW, 0.76–0.94 mm (0.90 ± 0.078) BWW and 0.56–0.68 mm (0.65 ± 0.095) SMW.

Description

Shell – holotype and paratypes ( Figure 2A–F ). Ovate-conical, translucent, 41 / 4 to 41 / 2 SWN, 1.56–1.82 mm TSL, 0.46–0.68 mm SSL, 0.64–0.72 mm SML, 1.00– 1.06 mm TSW, width of body whorl 0.76–0.94 mm BWW, 0.56–0.68 mm SMW .

Protoconch ( Figure 3A–C ). Five to eight whorls, sculpture reticulate (?), pores absent.

Radula ( Figure 3D–F ). Taenioglossate, rachidian tooth with one pair basal cusps, formula of rachidian tooth:

4 − 1 − 4 5 − 1 − 5 or; 1 − 1 1 − 1

lateral tooth with eight cusps (three at inner side, one largest, five at outer side); inner marginal tooth with 23–24 cusps, outer marginal tooth with 20 cusps.

Anatomy of adult male. Body unpigmented. Eyes present. Rectum L-shaped; penis bifid ( Figure 4A–D ). Right arm slender, stylet-shaped, with zigzagged vas deferens inside. Left arm (flagellum) broad, massive, with outlet of tubular penial gland situated apically. Penial gland narrow and short, coiled, proximally extended into the cephalic haemocoele.

Anatomy of adult female ( Figure 5 ). Body, eyes and rectum as in male. Pallial oviduct with ventral channel. Capsule gland hardly discernible from albumen gland, both glands relatively small. Bursa copulatrix large and bulbous. Bursal duct long. Coil of oviduct prominent, unpigmented. Two seminal receptacles, rs 2 (proximal) larger than rs 1 (distal).

Type locality

Sikiá (39 ◦ 22 ′ 07 ′′ N, 21 ◦ 37 ′ 53 ′′ E), Evrytania , Agrafa Mountains, Greece. This is a small, roadside well at an altitude of 774 m, with aquatic mosses .

Etymology

Type species. The generic name Agrafia refers to the Agrafa Mountains, the only known locality for this genus. The specific epithet wiktori refers to Prof. Andrzej Wiktor, a famous malacologist who has contributed greatly to the knowledge of the malacofauna of Greece.

Molecular phylogeny

For 18S, the Akaike Information Criterion, obtained with MODELTEST, selected the model SYM + I + Γ, with equal base frequencies; substitution rate matrix: [A-C] = 1.4302, [A-G] = 1.8232, [A-T] = 0.0823, [C-G] = 0.9251, [C-T] = 5.4497, [G-T] = 1.0000, proportion of invariable sites: (I) = 0.8059, and Γ distribution with the shape parameter = 0.9230.

For COI, the Akaike Information Criterion, obtained with MODELTEST, selected the model GTR + I + Γ, with base frequencies: A = 0.3483, C = 0.1285, G = 0.1189, T = 0.4043; substitution rate matrix: [A-C] = 0.2426, [A-G] = 8.3060, [A-T] = 0.1608, [C-G] = 1.4664, [C-T] = 13.6518, [G-T] = 1.0000, proportion of invariable sites: (I) = 0.4999, and Γ distribution with the shape parameter = 0.4263.

The 18S ML tree (not presented) shows A. wiktori (specimens 5F1–5F4) placed (as a paraphyletic group) within the Hydrobiidae clade, close to Hauffenia and the group consisting of Anagastina , Daphniola , Grossuana , Trichonia , Sadleriana , Radomaniola and Graziana . Unlike the other clades of the tree, the bootstrap support of the hydrobiid clade including Agrafia wiktori is high (BS = 98). The COI ML tree ( Figure 6 ) shows A. wiktori specimens belonging to a monophyletic, highly supported (BS = 93) clade, close to Hauffenia and Graziana , all within Hydrobiidae .

The combined 18S and COI ML tree ( Figure 7 ) shows the four specimens of A. wiktori belonging to a monophyletic, highly supported (BS = 97) clade, the sister clade of which consists of eight hydrobiid genera, including Hauffenia and Graziana . The large clade representing all Hydrobiidae is highly supported (BS = 94).

Figures

Figure 2. (A–F) Shells of Agrafia wiktori, bar represents 0.5 mm: (A, B) holotype, (C–F) paratypes.

Figure 3. Protoconch and radula of Agrafia wiktori, scanning electron micrographs: (A) Protoconch habitus; (B, C) protoconch surface; (D–F) radula; arrow indicates fragment of protoconch with more visible sculpture; bar represents: (A) 100 µm, (B) 25 µm, (C) 10 µm, (D–F) 5 µm.

Figure 4. Penis of Agrafia wiktori: (A, B) Dorsal view; (C) ventral view, with tubular penial gland; (D) the same tubular penial gland magnified; bar represents 0.5 mm for (A–C); arrow indicates outlet of tubular penial gland.

Figure 5. Renal and pallial section of female reproductive organs of Agrafia wiktori; bar represents 0.5 mm; bc, bursa copulatrix; cbc, duct of bursa copulatrix; ga, albumen gland; gn, capsule gland; gp, gonoporus; ov, oviduct; ovl, coil of (renal) oviduct; rs1, rs2, seminal receptacles 1 and 2 (after Radoman), respectively; vc, ventral channel.

Figure 6. Maximum likelihood phylogram for cytochrome oxidase subunit I (COI) sequences, bootstrap support (1000 replicates).

Figure 7. Maximum likelihood phylogram for combined 18S and cytochrome oxidase subunit I (COI) sequences, bootstrap support.