Grania dolichura Rota and Erséus, 2000
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publication ID |
https://doi.org/ 10.1080/00222930701391682 |
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persistent identifier |
https://treatment.plazi.org/id/FA09AD4F-FFFC-FFBD-28FE-529297E21A4D |
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Felipe |
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scientific name |
Grania dolichura Rota and Erséus, 2000 |
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Grania dolichura Rota and Erséus, 2000
( Figure 4A–C View Figure 4 ) Grania dolichura Rota and Erséus 2000, p 249 –252, Figure 3A–H View Figure 3 .
Material examined
WAM V 7308 , one subadult from Stn ES03-28 B and WAM V 7309 , one puberal specimen (spermathecae not fully differentiated) from Stn ES03-35 B.
Description
Body 9.7–10.5 mm long, 0.17 mm wide at V, 0.20 mm at XII, comprising 84, 85 segments. Prostomium small, bluntly conical, 60–80 mm wide and 48–55 mm long, epidermis 5.5– 6.0 mm thick at front ( Figure 4B View Figure 4 ). Chaetae ( Figure 4C View Figure 4 ) beginning in XVII–XVIII, in IV ventrally. Preclitellar chaetae up to 55 mm long, postclitellar chaetae up to 57 mm long. Epidermal gland cells conspicuous on anteriormost segments. A ‘‘copulatory gland’’ seen midventrally in XIV in puberal specimen. Spermathecal pores in lateral lines, slightly posterior to 4/5.
Head organ containing two large (5–6 mm) inclusions in both specimens ( Figure 4B View Figure 4 ); other inclusions may be present but coelomocytes partly impede observation of the region. Anterior septa 7/8–8/9 thickened. Pharyngeal glands showing no ventral lobes in IV, nor any extra pairs in VII. Gut contents: brown organic matter and diatoms. Rectal ampulla spacious, bowl-shaped, filling most of pygidium, ending in a broad anus. Coelomocytes numerous, rather large (16–19 mm long), filled with small, non-transparent, round granules ( Figure 4A View Figure 4 ). Dorsal blood vessel originating in L. Sperm sac reaching XXV. Sperm funnels three to fours times longer than wide (130–170 × 38–45 mm), cylindrical, with tall hyaline portion below collar. Sperm heads 20 mm long, with evident helical structure. Vasa deferentia unmodified, showing conspicuous inner ciliation, 11 mm thick near funnel, then narrowing to about 6–8 mm thick. Penial apparati with bipartite aglandular sacs and trumpet-like, entally funnel-shaped stylets, latter 21–25 mm long, 7 mm wide at junctions with vasa deferentia, terminating in a 1.5 mm wide tip. Stylets fully developed in puberal specimen. Each stylet housed in anterior portion of aglandular sac. Egg sac not developed. Spermathecal ampullae bulb- or pear-shaped, with small but evident inner cavity, empty (both specimens precopulatory). Ectal ducts narrow (18 mm), ectally bent, slightly expanded but devoid of glands at orifice.
Remarks
Neither of the Esperance specimens of G. dolichura is fully mature but both are consistent with the original description ( Rota and Erséus 2000) from Tasmania in diagnostic details of somatic (large size of head organ inclusions, long dorsal vessel, large chloragogen cells, thickening of anterior septa) and reproductive characters (clitellar pattern, penial bulb construction, stylet shape and size, length of sperm heads). From present observations on Tasmanian material (in E. R. collection), the two Australian populations are also consistent in the morphology of the rectum, a detail not noted previously. As concerns the pharyngeal glands, the Esperance specimens differ from the Tasmanian ones in lacking ventral lobes in IV and the extra glands in VII, while their sperm sacs extend more posteriorly. The new morphological information reported herein for G. bykane (head organ with four small globular inclusions, entally constricted penial stylets, etc.; see above) does not strengthen the possibility of a close relationship between the two species advanced by Rota and Erséus (2000).
Distribution and habitat
Originally reported from estuaries around Tasmania, where it is abundant and widespread (about 70 specimens from six stations) and covers a salinity range of 11–35psu, G. dolichura now appears to be a ‘‘southern Australian element’’ with a distribution possibly spanning across the Great Australian Bight and the South Australian Gulfs. Previously known as intertidal, in Esperance it is found in shallow subtidal (0.5–1.5 m) coarse sand colonized by Posidonia and in shelly heterogeneous sand.
( Figures 4D–G View Figure 4 , 5A View Figure 5 )
Grania ersei Coates, 1990 p 17–20 , Figures 1A–D View Figure 1 , 2 View Figure 2 ; Coates and Stacey 1993, p 406 –408, Figure 10A–F.
Material examined
WAM V 7310–7314 , five specimens numbered in this order: two from Stn ES03-5 B, two from Stn ES03-34 B, and one from Stn ES03-39 . SMNH Main Coll. 90228-90236, nine specimens: one from Stn ES03-4 B, two from Stn ES03-5 B, one from Stn ES03-21 C, and five from Stn ES03-34 A. MCZR Oligochaeta 0140–0145, six specimens: two from Stn ES03-1 B, two from Stn ES03-5 B, and two from Stn ES03-15 C. All specimens fully mature, except those from Stns ES03-1 B and ES03-39 , and one from ES03-15 C (puberal to precopulatory).
Description
Body 6.1–8.1 mm long (n 512), 0.15–0.24 mm wide at V, 0.17–0.29 mm at XII (n 516). Segments of adults 53–61 (n 512). Prostomium dome-shaped ( Figure 4D, E View Figure 4 ), 72–104 mm wide at 0/1, 56– 85 mm long (n 57), epidermis not always reduced at front (5–9.5 mm). Lateral chaetae beginning in XIV – XV, more rarely in XVI –XIX. Chaetal shaft straight, stout, 3.5–6 mm thick at mid-point, proximally bent into an oblique, rather long, narrow foot with indistinct heel and low instep; tip of foot straight ( Figure 5A View Figure 5 ). Preclitellar chaetae 50–70 mm long, with foot 13–19 mm long; postclitellar chaetae 54–75 mm long, with foot 16–23 mm long. Chaetal index 3.65, n 514, s 50.303. Maximal length of shaft around XVI and in caudal segments (72–75 mm), thickness greatest in anterior body region. In the two specimens from ES03-34 B, chaetae smaller, shaft length by thickness ranging within 40–56 by 2.5–5 mm. Epidermal gland cells inconspicuous .
Brain indented posteriorly. Head organ present, containing up to four equal- or unequalsized globules ( Figure 4D, E View Figure 4 ). Head organ not always detectable, partly because specimens on fixation had either everted their foregut or ejected refringent coelomocytes from head pore. Pharyngeal glands never extending into VII, always with ventral lobes in IV (one pair). Gut contents heterogeneous: both fine and coarse organic matter, undigested algal filaments, diatoms, fragmented sponge spicules. Rectal ampulla not or just enlarged at mid-length (olive-shaped). Nephridia not seen before clitellum. Coelomocytes numerous, narrow oval to drop-shaped, finely granular, refractile, up to 16 mm long ( Figure 4F View Figure 4 ). Dorsal blood vessel arising in XXV. Sperm sac extending into XVI –XIX (n 516). Sperm heads 15–18 mm long. Penial stylets ( Figure 4G View Figure 4 ) originating in posterior portion of penial apparatus, about 394– 500 mm long (n 54), fully formed also in puberal specimens devoid of spermathecae. An adult specimen from ES 03-5 A had two detached stylets at bottom of egg sac. Egg sac extending into XX–XXII (n 516). Ectal ducts of spermathecae very long, coiled, 13–14 mm thick, occasionally bearing a distinct, sessile ectal gland ( ES 03-4 B, ES 03-5 B). Sperm rings, 13– 18 mm in diameter, embedded in agranular walls of ental ampullar portion.
Remarks
The Esperance material gives the opportunity to complete the original and subsequent accounts of this Western Australian taxon (Albany: Coates 1990; Rottnest Island: Coates and Stacey 1993) with respect to the occurrence of coelomocytes, the different texture of the walls in the ectal and ental portions of the spermathecal ampulla, and the presence of a head organ (although not always detectable). The latter observation rectifies what was stated previously ( Rota and Erséus 2000, p 249; based on material in C. E. collection). Apparently, there is considerable variation in chaetal size among populations from different geographic areas (Albany: 42–112mm; Rottnest: 40–68 mm; Esperance: 50– 75 mm), but the values of the chaetal index are likely to be typically low, due to the proportionally long ental foot (see Coates 1990, Figure 1B View Figure 1 ; Coates and Stacey 1993, Figure 10 A, B). As noted in other species, the penial stylets (extremely long in G. ersei ) appear fully developed before complete differentiation of the spermathecae has taken place.
Distribution and habitat
South (Albany, Esperance ) and west ( Rottnest Island ) coasts of Western Australia. In intertidal and subtidal sands down to 26 m (new depth record), often among boulders and pebbles, with algal debris. This species can be locally very abundant: both previous accounts were based on rich collections (Albany material: 112 specimens from 26 stations; Rottnest material: 101 specimens from 25 stations) .
| WAM |
Western Australian Museum |
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Botanischer Garten und Botanisches Museum Berlin-Dahlem, Zentraleinrichtung der Freien Universitaet |
| SMNH |
Department of Paleozoology, Swedish Museum of Natural History |
| C |
University of Copenhagen |
| A |
Harvard University - Arnold Arboretum |
| MCZR |
Museo Civico di Zoologia |
| V |
Royal British Columbia Museum - Herbarium |
| E |
Royal Botanic Garden Edinburgh |
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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Grania dolichura Rota and Erséus, 2000
| Rota, Emilia, Wang, Hongzhu & Erséus, Christer 2007 |
Grania ersei
| Coates KA & Stacey D 1993: 406 |