Magnetia queenslandica, Hochberg & Cannon, 2003

Hochberg, Rick & Cannon, Lester R. G., 2003, Magnetia Queenslandica, A New Genus And New Species Of Typhloplanid Flatworm (Platyhelminthes: Rhabdocoela) From Magentic Island In North Queensland, Australia, Raffles Bulletin of Zoology 51 (1), pp. 1-6 : 3-5

publication ID	https://doi.org/ 10.5281/zenodo.4618688
persistent identifier	https://treatment.plazi.org/id/D576F552-FF89-2D30-D2CE-FD4276389FD0
treatment provided by	Carolina
scientific name	Magnetia queenslandica
status	sp. nov.

Treatment

Magnetia queenslandica , new species

( Figs. 2-7 View Fig View Fig View Fig View Fig View Fig View Fig )

Material examined. – Holotype – mature adult ( QM G218757 ), Horseshoe Bay , Magnetic Island, Queensland, Australia, coll. R. Hochberg, Nov.2001.

Paratypes – 4 mature adults ( QM G218758-61 ), same data as holotype, coll. R. Hochberg, Nov.2001 .

Description. – Specimens often translucent except for the gut and anterior rhabdite tracts, the latter is often dark brown under transmitted light ( Fig. 2 View Fig ). Body length 300-492 m and body width to 89 m at widest point in mid trunk region. In gliding animals, the head end is often stretched anteriorly and the trunk is in the shape of a bottle. Even in slightly contracted specimens, the head end is noticeably narrower than the trunk, often with an elongate neck-like region. Eyes are absent, but two distinct patches of rhabdites are present lateral to an anterior rhabdite fan and give the appearance of eyespots ( Figs. 2-4 View Fig View Fig View Fig ). The ciliated epidermis consists of columnar to cuboidal cells with cilia to 3-4 m long. Dermal rhabdites are present over most of the body except for a region ventral to the testes ( Fig. 2C View Fig ). Anteriorly, there is a prominent adenal rhabdite fan much darker than the rest of the body ( Figs. 2-4 View Fig View Fig View Fig ). All rhabdites are spindle-shaped and 5-6 m long. In a specimen 343 m long by 64 m wide, the rhabdite fan was 25 m wide and 40 m long. In crosssection, the anterior fan filled up ca. fifty percent of the body, the epidermis had indistinct cell borders, and few dermal rhabdites were present. Posteriorly, the rhabdite fan narrowed to a single rhabdite tract for approximately 40-50 m ( Fig. 2C View Fig ). The rhabdite tract then bifurcated and each fork expanded into several finger-shaped processes ( Figs. 2C View Fig , 3 View Fig ). In cross-section, the adenal rhabdites filled approximately one-third of the body. Dermal rhabdites were present in greater numbers in the trunk region. A caudal adhesive region was present as minute papillae at the posterior end ( Fig. 3 View Fig ). It is perhaps noteworthy that this region was indistinct in living specimens and only visible in a single stained wholemount (QM G218761).

The muscular system consisted of an outer layer of circular muscles and inner layers of longitudinal bands and several diagonal muscles ( Fig. 5 View Fig ). Other muscles were present around some of the reproductive organs described below.

The digestive tract consists of a saccate gut and pharynx rosulatus. The gut often contained diatoms. A verticallyoriented pharynx rosulatus is present in the posterior body region and up to 72 m diameter ( Figs. 2 View Fig , 3 View Fig , 5 View Fig ). Approximately ten to eleven eosinophilic glandular zones were symmetrically disposed around the perimeter ( Fig. 2C View Fig ; Paratype QM G218761).

The male reproductive system consists of paired testes, vasa deferentia, paired seminal vesicles, and a copulatory bulb m.

containing a sclerotic stylet ( Figs. 2-7 View Fig View Fig View Fig View Fig View Fig View Fig ). The paired testes are located at the anterior tip of the head and ventral to the adenal rhabdite fan ( Fig. 4C View Fig ). The testes extend posteriorly as tear-drop shaped sacs and are often longer than the rhabdite tracts in living animals. Vasa deferentia arise posteriorly from the testes and extend around the pharynx where they enlarge as pea-shaped seminal vesicles. A sperm duct arises medially from each seminal vesicle and opens into the proximal part of the male copulatory bulb located on the right side of the body. A weak supply of prostatic tissue is located within the anterior portion of the copulatory bulb. The copulatory bulb is oblong, to 38 m long, and covered in a delicate sheath of circular muscles. The copulatory stylet lies at the distal end of the copulatory bulb. The stylet is in the shape of a ‘boot’ and up to 19 m long with the distal tip pointing toward the body midline (Figs. 6,7). The proximal opening is up to 12 m in diameter that narrows to 5 m in the neck region before expanding to 12 m at the distal opening. The upper 8 m of the proximal region has irregularly thickened walls with transverse striations. Immediately below this are two thickened grooves, separated by 2-3 m, around the circumference of the neck ( Fig. 6 View Fig ). The distal opening is tear drop shaped. The stylet leads directly into the genital atrium by way of a short genital canal.

The female reproductive system consists of paired vitellaria, a single ovary, bursa copulatrix and receptaculum seminis ( Fig. 3 View Fig ). The paired vitellaria begin at approximately one-third body length. The vitellaria come in close contact with the solitary ovary but vitelline ducts were not observed. The ovary is located posterior and opposite the male copulatory stylet at the caudal end. The distal end of the ovary narrows before the oviduct expands into a seminal receptacle. The seminal receptacle connects to the lateral wall of the genital atrium. A weakly muscular bursa copulatrix communicated with the opposite wall of the genital atrium. A gonopore was not observed.

Etymology. – The species is named after the state of collection, Queensland. Gender feminine.

Locations. – Type locality - Horseshoe Bay (19 07’ S, 146 51’ E), Magnetic Island , Queensland, Australia. Second locality - Nelly Bay (19 09’ S, 146 51’ E), Magnetic Island GoogleMaps .