Grania hyperoadenia Coates, 1990

Wit, Pierre De, Rota, Emilia & Erséus, Christer, 2009, Grania (Annelida: Clitellata: Enchytraeidae) of the Great Barrier Reef, Australia, including four new species and a re-description of Grania trichaeta Jamieson, 1977, Zootaxa 2165, pp. 16-38 : 30-31

Grania hyperoadenia Coates, 1990

( Fig. 9 )

Grania hyperoadenia Coates, 1990: 25 –26, fig 6(1990).

New material examined: AMS main coll. W.35560: One incomplete (posteriorly amputated) whole-mounted specimen from Lizard Island, stn. L3.

Description: Length> 3.1 mm, segment number> 27. Prostomium 73 µm wide, 61 µm long; prostomial epidermis 20 µm thick on all sides. Width 113 µm at peristomium; 167 µm at IV; 134 µm at XII. Lateral chaetae present posteriorly from XV (from XVIII in original description); chaetae 50 µm long, L-shaped, entally bent into a slender, 15 µm long foot ( Fig. 9 A); chaetal index=3.49, n=6, sd=0.703. Clitellum in uneven rows of granular gland cells interspersed with hyaline gland cells at a frequency of about 2:1( Fig. 9 B). Head organ absent. Sperm sac extending to XVI, and egg sac extending to XVII (XIX and XX in original descr., respectively). Dorsal blood vessel commencing in XXV (XX in original descr.). Coelomocytes ( Fig. 9 C) abundant throughout body, oval, 12–16 µm across on the widest point, flattened, granular with unstained nucleus. Penial apparatus consisting of small invagination at male pore, surrounded by oval gland, 55 µm long and 40 µm wide (90 x 50 µm in original descr.); no stylet present. Spermatheca with ectal duct wedged into ampulla, about 50 µm long and 20–25 µm wide (84 x 16 µm in original descr.); ampulla roughly spherical, 40µm in diameter (89 µm in original descr.) ( Fig. 9 D).

Remarks: This specimen conforms to Coates’ (1990) original description of G. hyperoadenia from the Albany area (W Australia) with only minor differences, noted above. As G. hyperoadenia originally was described from a single specimen, this is the first record of variation in the species. The slight deviations concerning the first lateral chaetae as well as the length of the sperm and egg sacs are well within normal intraspecific variation ranges, when compared to other species. Both the glandular structure of the penial apparatuses and the spermathecae are smaller in this specimen than in the holotype of G. hyperoadenia . Our study provides the first information on the clitellar cell pattern, the coelomocytes and the head organ in the species.

Distribution and habitat: Albany area, south-western Australia and Lizard Island, Great Barrier Reef (new record). Subtidal sand, from 1.5 to 4 m depth.

Figures

FIGURE 9: Grania hyperoadenia Coates, 1990 (AMS main coll. W. 35560, stn. L 3). A: Chaeta. B: Clitellar gland cell pattern, dorsal view, anterior end to the top. C: Coelomocytes. D: Spermatheca, side view, anterior end to the bottom.