Tuatara: Volume 11, Issue 2, June 1963
New Zealand Land Slugs—Part 2
New Zealand Land Slugs—Part 2
(Continued from Tuatara, vol. 9, page 97)
In part I, a general account of the anatomy, habits, and derivation of the New Zealand native slugs was given. No key to the species or genera could be given in Part I as two of the four genera and twelve of the species had only recently been discovered, and descriptions of them had not been published elsewhere. Part II, therefore, comprises a key to the New Zealand and Subantarctic Athoracophoridae.
Since the publication of Part I, more information on the derivation of the New Zealand Athoracophoridae has come to light. (Solem, pers. comm.) Solem states that the New Hebridean slugs, in company with other slugs in the North, show a tendency towards grouping of the external orifices, a reduced or absent central radula tooth, and a reduction in the slime producing organs. By analogy with other groups, he concludes that these features show that the northern representatives of the group are more advanced than those in the south, and he thus argues that the group evolved in the north and then spread south to New Zealand and the Subantarctic islands.
Some of the specimens mentioned in the key have been described from a single specimen. In the main, these species come from areas where very little collecting has been done. Many species, such as Pseudaneitea schauinslandi and Athoracophorus maculosus have a very limited range, and much more collecting needs to be done before a comprehensive picture of the number of species and their distribution can be formed.
Key to the Genera of the N.Z. and Subantarctic Athoracophoridae
|1 (4)||Mantle area extending to perinotum.|
|2 (3)||Posterior lateral margin of mantle area straight; not more than 15 lateral grooves on either side.||Genus Athoracophorus Gould, 1852|
|3 (2)||Posterior lateral margin of mantle area runs diagonally forwards before recurving to run back to perinotum; more than 16 lateral grooves on either side.||Genus Reflectopallium Burton, 1963|
|4 (1)||Mantle area triangular, sometimes quadrangular, defined by grooves on all sides.|
|5 (6)||Anus not included in mantle area.||Genus Pseudaneitea Cockerell, 1891|
|6 (5)||Anus included in mantle area.||Genus Palliopodox Burton, 1963|
Fig. 1, Pseudaneitea papillata; fig. 2, P. dendyi; fig. 3, P. multistriata; fig. 4, P. gigantea; fig. 5, P. jonhsi; fig. 6, P. sorenseni; fig. 7, P. schauinslandi. An., anus; g.o., genital orifice; h.s., head shield; l.gr., lateral groove; m.a., mantle area; m.gr., median groove; p.a., pulmonary aperture; r.o., renal orifice.
Plates I-III are reproduced by courtesy of the Editor, Transactions of the Royal Society of New Zealand.
Key to the Species in the Genus Athoracophorus
|1 (2)||10 to 15 shallow lateral grooves on either side, colour variable, usually light buff or yellow, often with brown grooves and orange mantle area. No papillae. Widespread.||Athoracophorus bitentaculatus (Quoy and Gaimard) 1832|
|2 (3)||10 shallow lateral grooves on either side, each lying in a narrow buff stripe. Papillae broad and low, each surrounded by a circle of black spots.||A. maculosus Burton, 1963|
|3 (1)||12 lateral grooves on either side, papillae rare, mantle area produced posteriorly to 3/5 body length. Usually blackish, marbled with pale brown, with yellowish mantle area.||A. suteri Burton, 1963|
Key to the Species in the Genus Reflectopallium
|1 (2)||14 to 18 lateral grooves, all branching; low, rounded papillae, often fused into low ridges. Brownish grey, mottled with black.||R. pseudophyllum Burton, 1963|
|2 (3)||17 lateral grooves, mostly unbranched. 3 longitudinal rows of hemispherical papillae on either side. Colour dark grey, papillae white-tipped.||R. papillatum Burton, 1963|
|3 (4)||17 lateral grooves, mostly bifid; dorsum with very numerous, minute, hemispherical papillae.||R. delli Burton, 1963|
|4 (1)||18-20 lateral grooves. Anus contained within mantle area; colour buff, with irregular black spots.||R. martensi (Suter) 1909|
Key to the Species of the Genus Pseudaneitea
|1 (4)||Anus adjoining outer angle of mantle area.|
|2 (3)||Mantle area quadrangular. 17 lateral grooves, very few unbranched. Numerous irregular black spots on back. Campbell Is.||P. campbellensis Burton, 1963|
|3 (2)||Mantle area triangular. 15 lateral grooves, majority unbranched, median groove broad, shallow, and black. Back with numerous irregular black spots. West Coast, Fiordland.||P. gigantea (Suter) 1897|
|4 (1)||Anus close to perinotum.|
|5 (9)||Large papillae lacking.|
|6 (7)||20 lateral grooves, most unbranched. Back densely covered with small papillae. No preanal groove. Mason River, Canterbury.||P. aspera Burton, 1963|
|7 (8)||17 very deep lateral grooves, preanal groove present. Skin minutely granulate, back buff with numerous longitudinally arranged black spots. Picton.||P. gravisulca Burton, 1963|
|8 (5)||19 lateral grooves, most unbranched. Mantle area usually quadrilateral, low rounded ridges in some side fields. Dark grey or brown. Queenstown, Te Anau.||P. powelli Burton, 1963|
|9 (4)||Large papillae present in side fields.|
|10 (13)||Papillae conical.|
|11 (12)||22 narrow lateral grooves; up to 7 papillae in each side field. Dark grey with prominent tuberculate perinotal ridge. Stewart Is.||P. multistriata Burton, 1963|
|12 (11)||15-17 lateral grooves. Back olive green or dark grey, up to 5 black-tipped papillae in a side field. Widespread.||P. papillata (Hutton), 1878|
|13 (10)||Papillae rounded or hemispherical.|
|14 (16)||Preanal groove lacking.|
|15 (14)||13-15 lateral grooves; colour buff with irregular black streaks. Up to 4 papillae in a side field. Campbell Is.||P. sorenseni Powell, 1955|
|16 (14)||Preanal groove present.|
|17 (20)||Lateral grooves nearly all unbranched.|
|18 (19)||18-21 lateral grooves; up to 5 papillae in a side field. Light yellow with 2 rows of black spots flanking midline. Snares Is.||P. huttoni Suter, 1909|
|19 (18)||17 lateral grooves; up to 2 small papillae in a side field. Buff with irregular black spots. Ship Cove.||P. maculata Burton, 1963|
|20 (17)||More than 3 lateral grooves branching.|
|21 (22)||15 lateral grooves on either side. Papillae large, oval, crowded, 3-4 in each side field. Collingwood.||P. simrothi Suter, 1896|
|22 (23)||14-16 branching lateral grooves. Large rounded tubercular papillae in single row either side anterior to mantle area, double row posterior. Mantle area often quadrilateral. Dark grey. Mid-Canterbury.||P. dendyi Suter, 1897|
|23 (24)||16 lateral grooves, 2-3 large papillae in each side field. Colour grey, with triangular black spot on posterior apex of mantle area. D'Urville Is.||P. johnsi Burton, 1963|
|24 (20)||15 shallow lateral grooves, with 3-4 papillae in each side field. Back densely covered with small black spots. Pelorus Sound.||P. schauinslandi (Plate) 1897|
There is only one species in this genus. This is P. verrucosus (Simroth) 1889.
Diagnosis. 20 lateral grooves, nearly all unbranched. Papillae very numerous, small, conical. Colour uniformly black, or yellowish-brown with a median black stripe, and bands of black streaks and spots flanking the midline on either side. Auckland Islands.
|Mantle area.||An area, usually one-third of the distance along the back, defined by grooves and containing the renal orifice, the pulmonary aperature, and, in two species, the anus.|
|Perinotum.||A lateral ridge, delimiting the back, running along either side of the slugs from head to tail.|
|Side field.||Any area, apart from the mantle area, bounded by the median groove and two successive lateral grooves.|