The Classification and Reproductive Organs of New Zealand Land Planarians. Part IV.
[Received by the Editor, January 27, 1955.]
An account is given of the distribution and copulatory organs of the common land planarian Geoplana moseleyi. Five new species are described and their relationship with known species is discussed.
Description For synonymy and general description see Fyfe (1944, 1946). This is the most common land planarian collected in New Zealand and, being thick and tough, its survival, value is high. The shape of the living planarian is distinctive, the dorsal surface rising from the sides to a prominent ridge in the middle line so that in transverse section it would appear triangular. Within a great range of ground colour on the dorsal surface two characteristics are constant and are readily recognisable: (1) a median stripe paler than the ground colour and (2) numerous bluish-white slits (not spots) all over the surface. The ventral surface is paler than the dorsal, with numerous dark speckles. The average length is about 45 mm in a living specimen and 30 mm in a preserved one, but specimens as small as 13 mm long (preserved) have been found to be mature Two unusually large specimens measured (preserved) 68 mm long by 7 mm broad and 150 mm long by 15 mm broad, respectively.
In spite of the great variation in size there is sufficient constancy in external markings for these larger planarians to be recognised externally, the identification being confirmed by the structure of the genital organs.
Localities. G. moseleyi has been collected from the following localities:— Kohukohu, Opunake, Kapiti Island, Akatarawa divide, Jackson's Bay, Rahu, Franz Josef, Otira, Christchurch, Palmerston South, Dunedin district (both inland and on the coast), Fortrose district, Invercargill, Tuatapere, Doubtful Sound, Chatham Islands.
Copulatory Organs. G. moseleyi has no penis papilla but has a large penis bulb enclosing a wide irregular cavity and two accessory glands opening dorsally into a small genital atrium. One specimen collected at Akatarawa divide, 1500ft (length preserved 34 mm) shows the way in which a temporary penis papilla is formed for the discharge of sperms (Text-Fig. 1, fig. A). The penis bulb is pushed down and out so that it projects through the genital pore. At the same time the bulb is partly turned inside out so that the layer of cells which originally lined the atrial end of the bulb now forms the outer covering of the newly-formed papilla The proximal part of the bulb cavity which is drawn down with the bulb forms the cavity of the papilla, while the musculature is derived from the original muscles of the penis bulb.
The accessory glands which originally opened into the dorsal part of the atrium have changed their position and now open to the exterior at the base
Text-Fig. 1.—Geoplana moseleyi Hutton. A. Longitudinal sagittal section of copulatory organs with external penis. B. Copulatory organs in normal position.
Explanation of Text-Figures.
All the drawings were made with the aid of a camera lucida. The value of the projected scale is indicated in millimetres in each figure.
Abbreviations Used in Figures.
a, atrium; b, penis bulb; c, pharynx; d, seminal duct or common sperm duct; e, egg cells; f, female atrium; g, gland; h, glandular canal; I, glandular cavity, j, ejaculatory duct; k, spermiducal vesicle; l, glandular duct; m, male atrium; n, oviduct; o, mouth; p, genital pore; q, penis; r, glandular reservoir; s, seminal vesicle; t, intestine; u, glandular vesicle; v, prostatic vesicle; w, muscular flap showing 2 small adenodactyls cut across; x, adenodactyls; y, duct of adenodactyl; z, accessory gland.
of the penis papilla. From the position that the glands take up it can be assumed that their secretion is expressed during copulation.
Discussion. The formation of a temporary penis papilla has been described in other land planarians. In Rhynchodemus atropurpureus Hyman (1941) the folds of the male atrium can be erected to form a papilla. In Geoplana marginata (Marcus, 1951) part of the atrial wall, which is very much folded, forms a penis papilla, and the two sections of the atrium have different types of epithelium which can be distinguished when the papilla is not formed. In G. moseleyi the cells lining the cavity of the penis bulb are distinct from the ciliated atrial cells which are used to cover the proximal half of the outside of the papilla, the rest
of the covering being formed by the everted lining of the cavity. The cavity of the penis bulb has previously been called the seminal vesicle because it is a muscular tubular chamber near the exit of the sperm duct. The sperms, however, are not stored there but in an expansion of the vas deferens called the false seminal vesicle or spermiducal vesicle. A better name for the cavity of the penis bulb would be ejaculatory duct, since it has that function in the temporary penis papilla and does not appear at any time to store sperms.
A characteristic feature of Turbellaria is a rounded or oval body with a thick muscular wall and a cavity inside into which glands open. The gland cells may be situated in the layer of cells lining the cavity, in the muscular body or in the surrounding parenchyma. This type of organ is seen in the pharynx, the penis bulb, and in a variety of muscular gland organs which are associated with the copulatory apparatus. These are adenodactyls and accessory glands in triclads, and prostatoids and prostatic vesicles in the other classes of Turbellaria. The cavity of adenodactyls and accessory glands is divided into an inner glandular reservoir and a narrow muscular duct usually with a terminal vesicle opening into the atrium. Accessory glands are embedded in the wall of the atrium while adenodactyls project into the atrial cavity. Prostatoids and prostatic vesicles have a less elaborate structure with a simple cavity, are embedded in the body wall and usually open into the ejaculatory duct.
Although the above muscular gland organs which are associated with the copulatory apparatus have a general similarity in structure they are all constant and specific and probably could be used as a means of classification. Adenodactyls are regarded as the characteristic feature of the genus Artioposthia, and it is possible that the accessory glands of G. moseleyi are sufficiently important and distinctive to be generically significant.
Geoplana inaequabilis n.sp.
Material. Four specimens (No. 539) collected under logs at Kohukohu, North Auckland.
External Characters: G. inaequabilis is very mobile and extensible when living, and in the preserved state is unusually broad and thick, with a strongly convex dorsal surface. Length preserved, 58 mm. Dorsal surface uniformly dark mole. Ventral surface cream, closely speckled with mole. Anterior end red, dorsally. Eyes (Text-fig. 2, C.) in double row of large eyes at anterior end, eyes of each side end in front in large pigment spot; at sides of head small and large eyes very numerous, further back eyes arranged in an irregular diagonal pattern to posterior end. Mouth 33 mm from anterior end; genital pore 8 mm behind mouth. Pharynx branched.
Reproductive Organs: Ovary (Text-fig. 2, B.) 8 mm from anterior end, very long and narrow; oviduct leaves anterior part of ovary where it is surrounded by yolk cells; glandular canal with very long cilia enters atrium near ventral surface; vitellive glands compact, between branches of gut. Testes spherical, in ventral row. Sperm ducts, spermiducal ducts, common duct as usual. Short, wide glandular duct enters cavity of penis bulb, the proximal two-thirds of which forms a wide, slightly curved seminal vesicle with gland cells; distal third ciliated and non-glandular, forms male atrium continuous with common genital atrium; no penis papilla. Two accessory glands, open into atrium, one very large posteriorly, one small dorsally; each gland consists of small glandular
reservoir containing two kinds of secretion, coiled duct and terminal vesicle; lining of terminal vesicle ridged, with glandular and ciliated cells. Cells lining atrium have unusually long cilia especially at openings of accessory glands.
Discussion. Characteristic features of G. inaequabilis are the extensibility of the body and its broad, thick shape when fixed. Internal features are the long, narrow ovary, the two unequal accessory glands and the absence of a penis papilla. G. moseleyi has no penis papilla and two similar accessory glands, but they are always of the same size. Over a period of years the author has examined sections of the reproductive organs of approximately one hundred specimens of G. moseleyi which have been in varying stages of maturity, and in all of them the two accessory glands were of the same size. In all four specimens of G. inaequabilis the posterior accessory gland was much larger than the anterior one. There is also a distinct difference in the ovaries (that of moseleyi is spherical, of inaequabilis is long and narrow) and in the colouring, markings and shape. However, it may be advisable at a later stage to place these two species in one sub-family on account of the presence of accessory glands.
Type. One series of slides in the Department of Zoology.
Material: Two specimens (No. 492) collected under stones in bush, Dunedin.
Description: External Characters: Length living 55 mm. Dorsal surface (Text-Fig. 3A.) pale cream, unspeckled, with six longitudinal dark brown strips, arranged as follows:—Two narrow median lines of dark dots, two lateral broader and darker bands, two narrow marginal lines of dots. Ventral surface pale cream, unspeckled, median third paler than margins. Eyes in horseshoe round anterior end, extend to posterior end. Mouth 14 mm from posterior end, genital pore 9 mm from posterior end in a preserved specimen of 29 mm.
Reproductive Organs: Text-fig. 3B. Ovaries spherical, 2.75 mm from anterior end, diameter 0.22 mm; glandular canal long, narrow, entering female atrium near ventral surface; vitelline glands follicular. Testes pear-shaped, situated between the branches of the gut extending from the genital atrium to the anterior end. Sperm-ducts widen into spermiducal vesicles and join to form common sperm duct entering penis bulb; proximal part of bulb glandular, glands opening into two vesicles connected by narrow duct, lining of both vesicles ciliated and glandular, secretion staining differently. This glandular part resembles a prostatic vesicle which is similarly embedded in the walls of the penis bulb of some Rhabdocoels; distal part of penis bulb muscular surrounding narrow ejaculatory duct and small penis papilla. Two adenodactyls, long, narrow, at posterior end of atrium, each has long glandular cavity with narrow duct. One accessory gland dorsal, grandular, ciliated with ridged lining.
Discussion: Externally the dorsal markings are distinctive. Internally the reproductive organs present an unusual feature in having two adenodactyls an accessory gland and a type of prostatic vesicle. Land planarians with adenodactyls are placed in the genus Artioposthia.
Type. One series of slides in the Department of Zoology.
Material. Two specimens (Nos. 526B and 529) collected at Pipikaretu on the Otago Peninsula.
Text-Fig. 3.—A. and B. Artioposthia glandulosa n.sp. C.-F. Artioposthia polyadoides n. sp. A. Dorsal surface. B. Longitudinal sagittal section of copulatory organs. C. Dorsal surface D. Transverse section of ovary E. Longitudinal sagittal section of copulatory organs. Not all the adenodactyls are shown. One glandular vesicle is drawn and the free end of the other F. Glandular vesicle.
Description. External Characters: Length (preserved) 16 mm. Dorsal surface (Text-fig. 3C) light tan with sparse dark red flecks and four dark red stripes arranged as follows:—Two narrow median and two broad lateral approximately equidistant from each other. Anterior end tan, slight median groove ventrally. Ventral surface light tan unspeckled. Mouth 10 mm from posterior end. Genital pore 2 mm behind mouth. Eyes very large and evenly spaced round anterior end and along sides. Pharynx tubular.
Reproductive Organs: Ovaries (Text-Fig. 3D) paired, spherical, one-third of distance from pharynx to anterior end; egg-cells form wide shallow cap on anterior edge of ovary; oviducts join posteriorly to form glandular canal entering genital atrium opposite genital pore. Yolk glands follicular.
Testes small, oval, ventral restricted to central region; vas deferens slightly enlarged to short, thin-walled spermiducal vesicle, two ducts join in penis to form ejaculatory duct. There is no true seminal vesicle, the spermiducal vesicles taking its place. Penis muscular, with large papilla (Text-fig. 3E.) Genital atrium partially separated into male and female portions Six large compact adenodactyls on dorsal atrial wall, two opening into female atrium, and four into male atrium, each enclosing crescentic reservoir and narrow duct; muscular flap carrying four smaller adenodactyls of same type projects into male atrium from each side. Two glandular vesicles (Text-fig. 3F.) open into male atrium close to penis papilla. They are larger and more loosely muscular than the adenodactyls and resemble the prostatic vesicles of polyclads in being closely associated with the penis papilla and producing a secretion which mixes with sperms round the base of the papilla. The secretion comes from a special glandular cavity which opens into a reservoir with thin-walled duct.
Discussion. Adenodactyls are characteristic of the genus Artioposthia. Specific characters are the large number of adenodactyls and two prostatic vesicles. The position of mouth nearer the anterior than the posterior end is a very unusual feature.
Type. Eight slides in the Department of Zoology.
Material. A number of specimens (Nos. 541, 542, 546) collected under logs at Kohukohu, North Auckland.
Description. External Characters: A long thin planarian when alive, length preserved, 6.5 mm to 13 mm; breadth 3 mm in a planarian 13 mm long. Body rounded with marginal bands replacing usual edge between dorsal and ventral surfaces (Text-fig. 4C.). Dorsal surface (Text-fig. 4D.) has general appearance of dark mole colour due to speckles of dark mole closely set on a background of tan, speckles running together at the margins, median narrow dark mole stripe on pale background; marginal bands dark mole separated from dorsal surface by narrow cream stripe. Ventral surface cream with faint mole speckles more conspicuous at anterior end. In younger specimens ventral surface light mole with three narrow tan or cream stripes, one median and two lateral. Eyes of approximately same size, set apart in single ring round anterior end, in wide irregular zig-zag along sides of body to posterior end. Mouth 6 mm from anterior end in planarian of 11 mm; genital pore 2 mm behind mouth. Pharynx tubular with dorsal insertion posterior to ventral.
Reproductive Organs. (Text-fig. 4A). Ovaries paired, spherical, 3 mm from anterior end; diameter 0.242 mm; glandular canal enters atrium dorsally.
Text-fig. 4.—Geoplana circularis n. sp. A. Longitudinal sagittal section of pharynx and copulatory organs. B. Side view of anterior end with eyes. C. Diagrammatic transverse section of body of young planarian to show rounded margins and arrangement of stripes. D. Dorsal surface.
Vitelline glands lobulated, between branches of gut. Testes oval, ventral, restricted to small area anterior to pharynx. Seminal duct ciliated, contains secretion of gland cells; seminal vesicle lined with gland cells; ejaculatory duct in penis papilla. Cells lining atrium have very short cilia; epithelium high in female part.
General anatomy: Circular muscle layers very firm and compact. Ventral nerves are distinct cords and not diffuse plates.
In several of the smaller specimens the mouth only was visible (often with tubular pharynx protruded). In one of these which was sectioned, the atrium was beginning to form, the ovary was well-developed, but no testes were visible, an indication that the female organs develop before the male ones.
Remarks. The colouring and markings of G. circularis are distinctive. The rounded shape without margins is unusual. The copulatory apparatus with a well-developed penis bulb and papilla is similar to that commonly found in land planarians of other countries and differs from that of the majority of New Zealand land planarians in which the penis bulb and papilla are usually either reduced or absent, and prominent accessory gland organs replace them as copulatory organs.
G. circularis has a certain resemblance to G. atra Fr. Mull (Graff, 1899). The size and shape of the body with rounded margins is similar. Preserved specimens of G. atra measured 19 mm by 1 mm and 16 mm by 1.2 mm, which is slightly longer and thinner than G. circularis. On the dorsal surface G. atra lacks the median dark line of G. circularis the copulatory apparatus is similar but in G. atra there is a definite separation of the atrium into male and female parts and the penis papilla is larger Other differences are: in G. atra the dorsal insertion of the pharynx is at the same level as the ventral, in G. circularis the dorsal insertion is posterior to the ventral. In G. atra the eyes are densely packed and extend over the back behind the head of the body but are wide apart in G. circularis The above differences are considered sufficient to make a new species.
Type. One whole specimen and a series of slides in the Department of Zoology.
Text-fig. 5.—Geoplana cyanea n.sp. A. Longitudinal sagittal section of copulatory organs B. Dorsal view of anterior end with eyes. C. Diagrammatic transverse section of body D. Dorsal surface.
Geoplana cyanea n. sp.
Material. A number of specimens of an unusual vivid blue colour, collected at Napier.
Description. External Characters: Length living, extended, 35 mm, fixed, 26 mm. Dorsal surface very slimy, with many gland cells in epithelium and bunches of glands in mesenchyme; stone coloured with median and lateral white lines. In young, immature specimens there is a dark line in the centre of the median pale stripe. Margins rounded, the dorsal colour extending to ventral surface. Ventral surface has general appearance of ultramarine blue due to tiny blue spots arranged closely and evenly on a light ground, blue colour darker towards margins. Anterior end tan. Eyes round anterior end in single row wide apart, larger at side of head, smaller end at equal distance apart to near posterior end. Mouth 16 mm from anterior end in planarian of 28 mm; genital pore nearer mouth than posterior end Pharynx long and tubular, ventral attachment anterior to dorsal.
Reproductive Organs: Genital atrium divided by a flap into male and female atria both lined with ciliated epithelium Ovary spherical, about half-way between anterior end and pharynx, capsule of ovary very thin; glandular canal short, opening into female atrium; vitelline glands between branches of gut. Testes pear-shaped, ventral, extending from genital pore to anterior end, vasa deferentia
slightly enlarged to spermiducal ducts which join and enter coiled seminal vesicle in penis bulb. Penis papilla blunt, enclosing ejaculatory duct.
Discussion. G. cyanea is characterised externally by the vivid blue colour of the ventral surface, which is very different from the usual cream or brown colour. Internally the genital complex is simple, with conspicuous penis papilla. G. spenceri Dendy (1891) has a ventral surface of “cobalt blue” which would appear from the figure to be a much lighter shade than that of G. cyanea; it is also twice the size and differs in other details.
Type. One whole specimen and a series of slides in the Department of Zoology.
The thanks of the author are due to Professor B. J. Marples, Dr. J. T. Salmon and Miss K. Paviour-Smith for specimens collected by them.
Dendy, A., 1890. The Anatomy of an Australian Land Planarian. Trans. Roy. Soc. Victoria, 1, Pt. 11, pp. 50-95.
Fyfe, Marion L, 1944. Classification and Reproductive Organs of New Zealand Land Planarians. Pt. I, Trans. Roy. Soc. N.Z., 74, pp. 288-293.
Fyfe,Marion L, 1946. Classification and Reproductive Organs of New Zealand Land Planarians. Pt. II, Trans. Roy. Soc. N.Z., 76, pp. 135-138.
Graff, L. Von, 1899. Monographie der Turbellarien. 2. Tricladida terricola W. Engelmann, Leipzig.
Marcus, Ernesto, 1951. Turbellaria Brasileiros (9). Bol. Fac. Fil. Zool n. 16, pp. 5-215. Sao Paulo.
Miss Marion L. Fyfe, M.Sc.Department of Zoology
University of Otago