Cratera steffeni Rossi, Fontoura, Amaral & Leal-Zanchet, 2014, sp. nov.
Creators: name: Rossi, Ilana
name: Fontoura, Marcela
name: Amaral, Silvana
name: Leal-Zanchet, Ana M.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Platyhelminthes
Turbellaria
Tricladida
Geoplanidae
Cratera
Cratera steffeni

description: Cratera steffeni sp. nov.
Geoplana sp. 3: Baptista et al., 2006
Geoplana sp. 3: Fick, Leal-Zanchet & Vieira, 2006 Geoplana sp. 9: Leal-Zanchet & Baptista, 2009 Geoplana sp. 7: Leal-Zanchet et al., 2011
Etymology. The specific name is in honor of the naturalist MSc. Clemente José Steffen S.J. (in memoriam) and his relevant contribution to the ethnobotany in southern Brazil.
Type material. Holotype: MZUSP PL.1557: leg. I. Fick, 31. March 2000, Cambará do Sul, RS, Brazil – anterior tip: transverse sections on 28 slides; anterior region at the level of the ovaries: sagittal sections on 33 slides; anterior region at the level of the anteriormost testes: sagittal sections on 83 slides; pre-pharyngeal region: transverse sections on 18 slides; pharynx: sagittal sections on 29 slides; copulatory apparatus: sagittal sections on 34 slides; Paratypes: MZU PL.00176: leg. I. Fick, 0 7. August 2001, Cambará do Sul, RS, Brazil – anterior region on the level of the ovaries: horizontal sections on 19 slides; pre-pharyngeal region: transverse sections on 16 slides; pharynx: sagittal sections on 38 slides; copulatory apparatus: horizontal sections on 16 slides; MZU PL. 00177: leg. I. Fick, 24. March 2002, Cambará do Sul, RS, Brazil – preserved on clove oil; MZU PL. 00178: leg. I. Fick, 21. April 2002, Cambará do Sul, RS, Brazil – anterior tip: transverse sections on 22 slides; anterior region on the level of the ovaries: sagittal sections on 23 slides; pre-pharyngeal region: transverse sections on 10 slides; pharynx: sagittal sections on 24 slides; copulatory apparatus: sagittal sections on 34 slides; MZU PL. 00179: leg. J. Bencke, 0 1. September 2002, Cambará do Sul, RS, Brazil – copulatory apparatus: sagittal sections on 20 slides.
Type-locality. Cambará do Sul, state of Rio Grande do Sul (RS), Brazil.
Distribution. Rio Grande do Sul (Cambará do Sul), Brazil.
Diagnosis. Body elongate with parallel margins, anterior tip rounded and posterior tip pointed. Live specimens with a broad orange band, bordered by two black paramarginal stripes on the dorsal surface. Eyes dorsal, but restrict to a lateral band on each side of the body, without clear halos; conspicuous glandular margin with four types of secretory cells; mc:h, 9%–10%; pharynx bell-form; esophagus short; anteriormost testes posterior to ovaries; sperm ducts opening laterally into the proximal portion of the prostatic vesicle; prostatic vesicle extrabulbar, unpaired, with ample proximal portion and tubular distal portion; ovovitelline ducts emerging dorso-laterally from the posterior half of ovaries, and ascending laterally to the female atrium; common ovovitelline duct short; vagina long, dorso-anteriorly curved; female and male atria with almost the same length; no folds separating male and female atria.
Description. External morphology. Body elongate with parallel margins, anterior tip rounded and posterior tip pointed. When creeping, maximal length reaches 68 mm in the holotype (Table 1). Mouth distance from anterior tip, 68%; gonopore distance from anterior tip, 86.5% relative to body length in the holotype (Table 1).
Alive, dorsum with orange pigmentation constituting a broad band, bordered by two black paramarginal stripes. Under the stereomicroscope, pale-yellow dorsal ground-colour visible on body margins. Ventral surface pale yellow. After fixation, the dorsal band becomes greyish and the paramarginal stripes, brown (Figs 1–2); the ventral surface remains pale yellow. Dorsal band with maximum width of 2.6 mm, corresponding to 44% of body width in the holotype. Paramarginal stripes begin close to the anterior tip and end next to the posterior tip, converging towards both extremities of the body (Fig. 1); they are 0.7 mm wide (12% of body width in the holotype).
Eyes, initially uniserial, surround anterior tip (Figs. 3 ̶4). After the first millimeter, eyes become pluriserial and form a lateral band on each side of the dorsal surface. Three to four eyes occur on the same transversal level, being more numerous in the median third of the body (Fig. 5), occupying a band of about 0.7 mm on each side of the body (12.5% of body width). They become less numerous and uniserial towards posterior tip (Fig. 3). Eyes monolobated; they are small in the first millimeter of the body (about 19 µm in diameter). After that, they are mixed with larger eyes (30µm–36 µm in diameter). Clear halos are absent.
Internal morphology. Sensory organs, epidermis and body musculatures. Sensory pits, as simple invaginations, about 25 µm to 30 µm deep, contouring anterior tip, distributed ventromarginally in a single row (Figs. 6 ̶7). They occur initially at intervals of about 24 µm, posteriorly becoming gradually sparser until they disappear approximately at 6 mm from anterior tip (approximately 14% of body length in the holotype).
Creeping sole occupying the whole body width in the holotype (Table 1). Three types of secretory cells discharge through dorsal epidermis and body margins of the pre-pharyngeal region: numerous rhabditogen cells with xanthophil secretion (rhammites) and cells with amorphous cyanophil secretion, as well as scarcer cells with coarse granular xanthophil secretion. Creeping sole receives the secretion from abundant coarse granular cyanophil glands and few rhabditogen cells with small, xanthophil rhabdites. Glandular margin (Figs. 8–9) receiving at least four types of granular secretion: abundant glands with xanthophil coarse granules as well as numerous glands with ill-stained fine granules and scarcer xanthophil and cyanophil glands with fine granules. On anterior tip, numerous glands with cyanophil coarse granular secretion and scarcer cells with coarse granular xanthophil secretion open through the creeping sole, whereas few rhabditogen cells with small, xanthophil rhabdites and cells with amorphous cyanophil secretion open through the whole surface of the body.
Cutaneous musculature with the usual three layers (circular, oblique and longitudinal layers), longitudinal layer with thick bundles (Figs. 6 ̶11, Table 2). Cutaneous musculature thinner in the pre-pharyngeal region than in the anterior region of the body, but gradually diminishing towards anterior tip. Musculature higher medially, becoming progressively lower towards body margins; ventral musculature higher than dorsal at the sagittal plane. Mc:h 9% in the holotype (Table 2).
Mesenchymal musculature (Figs. 6 ̶8, 10̶11) well developed, mainly composed of three layers: (1) dorsal subcutaneous, located mainly close to the cutaneous musculature, with oblique fibers variously oriented (about 8–12 fibers thick); (2) supra-intestinal transverse (about 18̶20 fibers thick); (3) sub-intestinal transverse (about 6̶8 fibers thick). In addition, there are scattered transverse subneural fibers, ventral subcutaneous oblique fibers, as well as numerous dorsoventral ones. On the anterior region of the body, the mesenchymal musculature is more developed than in the pre-pharyngeal region.
Pharynx. Pharynx bell-form, 2.8 mm in length, with dorsal insertion located at the beginning of median third of pharyngeal pouch; mouth posterior to the dorsal insertion, in the median third of pharyngeal pouch (Fig. 12). Esophagus short with folded wall; it is lined by cuboidal ciliated epithelium with insunk nuclei. The esophagus is coated with a thick circular subepithelial muscle layer, followed by longitudinal fibers, some of them mixed with the circular fibers (120 µm–180 µm thick). Esophagus: pharynx ratio, 10% in the holotype. Pharynx and pharyngeal lumen lined by ciliated cuboidal epithelium with insunk nuclei. Pharyngeal glands constituted by three secretory cell types: abundant secretory cells with fine granular erythrophil secretion; cells with amorphous cyanophil secretion; and cells with fine granular xanthophil secretion. Cell bodies of pharyngeal glands located in the mesenchyme, mainly anterior and laterally to pharynx. Pharyngeal outer musculature (30 µm – 40 µm thick) comprised of thin subepithelial layer of longitudinal muscles, followed by a thicker circular layer, mixed internally with numerous longitudinal fibers. Circular layer becomes as thin as longitudinal one towards pharyngeal tip. Inner pharyngeal musculature (100 µm–150 µm thick) comprises a thick circular subepithelial layer, mixed with longitudinal fibers. Inner musculature gradually becomes thinner towards pharyngeal tip.
Reproductive organs. Testes in one irregular row beneath the dorsal transverse mesenchymal muscles (Figs. 8, 10). They begin posteriorly to the ovaries and extend near to the root of the pharynx (Table 1). Sperm ducts medial to ovovitelline ducts in pre-pharyngeal region. They form spermiducal vesicles posteriorly to pharynx. Distally, spermiducal vesicles enter laterally into the proximal expanded portion of the prostatic vesicle (Fig. 14). Extrabulbar prostatic vesicle, unpaired, located near to the common muscular coat, with ample proximal portion and tubular distal portion. The proximal portion shows a laterally expanded, T-shaped form (Figs. 15, 17, 18) that is closer to the ventral epidermis than to the dorsal epidermis. Τhe prostatic vesicle penetrates the common muscular coat, becoming sinuous, and continues, inside the penis papilla, as an ejaculatory duct. Ejaculatory duct almost straight, opening through an expansion into the tip of the penis papilla (Fig. 19). Male atrium unfolded, occupied by the conical and symmetrical penis papilla (Table 1, Figs. 14 ̶17).
Lining epithelium of sperm ducts cuboidal and ciliated; thin muscularis (3 µm) mainly constituted of circular fibers. Prostatic vesicle lined with ciliated tall columnar or pseudo-stratified epithelium, receiving abundant fine granular erythrophil and amorphous cyanophil secretions, both from secretory cells with bodies lying in mesenchyme, mainly around vesicle. Muscularis of prostatic vesicle (about 40 µm–80 µm thick) comprises interwoven longitudinal, oblique and circular fibers (Figs. 16–18). Ejaculatory duct lined with ciliated columnar epithelium, receiving few openings from secretory cells with weakly cyanophil, amorphous secretion. These glands show intrapapillar cell bodies. Muscle coat of ejaculatory duct thin (5 µm–10 µm thick), mainly constituted of circular fibers.
Penis papilla lined with non-ciliated columnar epithelium with apical xanthophil layer. The epithelium becomes flat towards the tip of the papilla (Figs. 16–17, 19). Penis glands with fine granular xanthophil and erythrophil secretions as well as cyanophil amorphous secretion. They run longitudinally in the papilla, with numerous openings into the male atrium through its lining epithelium (Figs. 16–17). Erythrophil and cyanophil glands present cell bodies external to common muscle coat among fibers of this coat; xanthophil cells, intrapapillar cells bodies. Muscularis of the penis papilla (25 µm) composed of a subepithelial circular layer and a longitudinal subjacent layer.
Epithelial lining of male atrium columnar (20 µm–30 µm), non-ciliated. Epithelial cells with xanthophil apical secretion, higher in the distal portion of the male atrium. Four types of glands empty through this epithelium: abundant cells with fine granular, cyanophil secretion; cells with fine granular erythrophil secretion; cells with cyanophil amorphous secretion; cells with fine granular xanthophil secretion. Numerous necks of cyanophil glands concentrate their openings through the dorsal wall of the male atrium (Fig. 20). Muscularis of male atrium (15 µm) comprised of circular subepithelial fibers and subjacent longitudinal fibers.
Vitellaria, situated between intestinal branches, open into the ovovitelline ducts. Ovaries ovoid, measuring about 250 µm in diameter in the holotype. Ovovitelline ducts emerge dorso-laterally from the posterior half of ovaries (Fig. 13) and run posteriorly immediately above the nerve plate. Laterally to the female atrium, ovovitelline ducts ascend posteriorly and medially inclined, to unite dorsally to the ental part of female atrium, thus forming a short common glandular ovovitelline duct. Ental portion of female atrium presents a long, dorso-anteriorly curved diverticulum (vagina) (Figs. 14–22). Female atrium funnel-shaped with folded walls (Figs. 14 ̶17). Female atrium length almost the same as male atrium length in the holotype (Table 1).
Paired ovovitelline ducts and common oviduct lined with ciliated, cuboidal to columnar epithelium, and coated with muscularis comprising mixed circular and longitudinal muscle fibers (5 Μm – 10 Μm thick). Abundant shell glands with xanthophil secretion empty into almost the whole ascending portion of paired ovovitelline ducts and common glandular ovovitelline duct (Figs. 14, 15, 21–23).
Female atrium lined by tall columnar epithelium exhibiting irregular height and multilayered aspect in some places (Figs. 16, 23); with xanthophil apical surface. Vagina lined with columnar to pseudostratified epithelium, ciliated in its proximal portion. Vagina and female atrium receive abundant erythrophil and xanthophil granular secretions as well as cyanophil amorphous secretion. Cell bodies of cyanophil and erythrophil glands are located between fibers of the atrial stroma or external to the common muscle coat and those of xanthophil cells are internal to the common muscle coat. Muscularis of vagina and female atrium (20 µm thick) composed mainly of circular fibers mixed with some longitudinal fibers.
Gonopore canal vertical at the sagittal plane. Male and female atria with ample communication, without separating folds (Figs. 14 ̶17). Gonopore canal lined with ciliated columnar epithelium, receiving the openings of abundant rhabditogen cells and scarcer glands containing amorphous cyanophil secretion as well as glands with fine granular erythrophil secretion. Muscularis of gonopore canal comprised of circular subepithelial fibers and subjacent longitudinal fibers.
Common muscle coat with circular, longitudinal and oblique fibers, thickest entally and along dorsal wall of male, thinner around female atrium. A stroma with sparse mixed muscle fibers separates the atrial muscularis and common muscle coat.
Remarks. Vitellaria well-developed in the holotype and paratypes MZU PL.00176 e MZU PL.00179. The not fully mature paratype MZU PL.00178 shows the dorsal insertion of the pharynx located at the end of the anterior third of the pharyngeal pouch, which is thus anteriad-shifted in relation to the holotype and other paratypes.
description: Published as part of Rossi, Ilana, Fontoura, Marcela, Amaral, Silvana & Leal-Zanchet, Ana M., 2014, A new species of land flatworm (Platyhelminthes: Continenticola) from areas of Araucaria Forest in southern Brazil, pp. 514-524 in Zootaxa 3794 (4) on pages 515-523, DOI: 10.11646/zootaxa.3794.4.2, http://zenodo.org/record/227062