Grania cinctura, Wit, Pierre De & Erséus, Christer, 2007

Wit, Pierre De & Erséus, Christer, 2007, Seven new species of Grania (Annelida: Clitellata: Enchytraeidae) from New Caledonia, South Pacific Ocean, Zootaxa 1426, pp. 27-50 : 33-36

Grania cinctura sp.n.

( Figure 3 , Table 1)

Holotype: SMNH type coll. 6559, whole-mounted specimen from Lifou, stn. NC00-17.

Paratypes: SMNH type coll. 6560-6564, 5 whole-mounted specimens from Lifou, 4 of which from type locality, and 1 from stn. NC00-18; SMNH type coll. 6565-6568, 6572, 5 whole-mounted specimens from Touho: 1 from each of stns. NC93-10, NC93-12, NC93-13, NC93-29 and NC93-33.

Other material examined: SMNH main coll. 87866-87882, 17 specimens from CENTOB collected off Nouméa, New Caledonia, during the Nouvelle Calédonie 78 excursion in 1978 (stn. NC78-42); SMNH main coll. 87884-87924, 41 specimens from Touho (stns. NC93-9, NC93-10, NC93-11, NC93-12, NC93-13, NC93-14, NC93-16, NC93-25, NC93-29, NC93-33, NC93-50 and NC93-59); SMNH main coll. 87927- 87956, 30 specimens from Lifou (stns. NC00-17 and NC00-18).

Species Chaetal distribution Penial bulb shape Spermathecal shape Grania novacaledonia

Grania cinctura Grania galbina Grania curta Grania fustata Grania papillata Grania fiscellata Description of type material: Body 7.4–9.5 mm long (n=11), 0.21–0.26 mm wide at III, 0.23–0.27 mm at clitellum (n=10). Segment number 42–54 (n=11). Prostomium rounded, 90–120 μm wide, 70–75 μm long (n=10); epidermis 23–28 μm thick on occipital lobes, 15–25 μm on upper lip (n=9), 5–18 μm at front side (n=8). Peristomium 165–205 μm wide at 1/2 (n=9). Preclitellar chaetal distribution highly variable, ventral chaetae commencing in VI but frequently missing from one or more segments, most often IX and X; chaetae absent in XII; lateral chaetae commencing in XXI–XXIV. Chaetae of uniform size throughout body, 65–80 μm long (n=15); chaetae L-shaped with conspicuous heel, in pre-clitellar segments almost T-shaped due to size of heel; foot 17–27 μm long (chaetal index=4.78, n=15, sd=0.98) ( Figure 3 A). Epidermal gland cells inconspicuous. Clitellum 20–25 μm thick, starting in XII and extending to mid XIII, in the shape of uneven transverse rows consisting of granular gland cells interspersed with hyaline cells at a ratio of about 2:1, except near male pores where hyaline cells are absent ( Figure 3 B). “Copulatory glands” not observed in XIV. Spermathecal pores lateral, located right behind 4/5. Male pores located ventrolaterally in mid XII.

Brain in II–III, posteriorly indented in “head” region. No true “head organ” present, but bilobed vesicle present immediately behind 0/1, dorsal to the anterior furcation of blood vessel, between the circumpharyngeal commissures; no inclusions present, but hollow compartments visible which seem to be internally ciliated. Pharyngeal glands located from 4/5 to 6/7, not united dorsally; dorsal lobes present in IV – VI, ventral lobes present in IV (1 pair), V (2 pairs) and VI (2 pairs); largest in VI, indenting septum 6/7 slightly into VII ( Figure 3 C). First pair of nephridia at 7/8. Dorsal blood vessel commencing in XXIII–XXVI. Chloragogen cells small (5–7 μm tall). Coelomocytes not observed. Sperm sac extending posteriorly from clitellum as far back as XV. Sperm funnels of uniform width, 40–50 μm wide, 6–7 times as long as wide. Heads of spermatozoa 15–20 μm long. Vasa deferentia long, unmodified, loosely coiled in XII to XIV; 6 μm wide, internally ciliated. Penial apparati ( Figure 3 D) uniform oval glandular structures, 50–65 μm long, 45–50 μm wide, with vasa deferentia opening into epidermal invagination (Penial bulb type 3). Stylets absent. Egg sac reaching as far back as XIX. Spermathecae ( Figure 3 E) attached to oesophagus near 5/6; ampullae roughly spherical, 50– 55 μm in diameter, ectal ducts bipartite, with ental part of uniform width, 40–45 μm long and 25 μm wide, ectal part covered by glandular cells; 4–8 sperm rings per spermatheca, 13–18 μm in diameter, located throughout ampullae; no glands at spermathecal pores.

Etymology: Named by the Latin cinctura , which is a form of Roman girdle. This refers to this species having a thick clitellum which obscures the male genitalia in many specimens.

Remarks: As in G. novacaledonia , the pre-clitellar chaetal distribution is irregular. Grania cinctura , however, is most frequently equipped with chaetae in all segments but one or two (IX–X), which is a distribution resembling that of G. atlantica Coates & Erséus, 1985 and G. m i r a Locke & Coates, 1998. In addition, the penial bulb structure is similar to that of G. a t l a n t i c a, which is an Atlantic deep-sea species. The spermatheca, however, is distinct with its bipartite ectal duct, where the ectal part is covered by glandular cells. Neither G. atlantica nor G. m i r a possess any gland cells on the spermathecal duct.

Other characters in common with G. novacaledonia are the bilobed vesicles present anterior to the brain (see Remarks under G. novacaledonia and Discussion), and the apparent lack of coelomocytes (see Remarks under G. novacaledonia ). The two are easily distinguished from each other, however, by the size difference ( G. cinctura is much larger), and by the shape of the spermatheca.

Distribution and habitat: Touho and Nouméa areas, New Caledonia, and Lifou, Loyalty Islands, lower intertidal to shallow subtidal (6 m), medium to coarse sand.

Figures

FIGURE 3. Grania cinctura sp. n.. A: Chaetae. B: Clitellar cell pattern. C: Overview of I – VI. D: Penial apparatus. E: Spermatheca.