Schockaertia aprostatica, Diez & Monnens & Wuyts & Brendonck & Reygel & Schmidt-Rhaesa & Artois, 2023

Diez, Yander L., Monnens, Marlies, Wuyts, Arlien, Brendonck, Luc, Reygel, Patrick, Schmidt-Rhaesa, Andreas & Artois, Tom, 2023, Taxonomy and phylogeny of Dalytyphloplanida Willems et al., 2006 (Platyhelminthes: Rhabdocoela), with the description of a new family, a new genus, and sixteen new species from Cuba and Panama, Organisms Diversity & Evolution (New York, N. Y.) 23 (4), pp. 631-681 : 641-645

publication ID

https://doi.org/ 10.1007/s13127-023-00623-w

publication LSID

lsid:zoobank.org:pub:4D2516BA-19CF-46C6-8D96-F17DD505B4FF

persistent identifier

https://treatment.plazi.org/id/C8BB595A-E09B-4A05-8DA9-1FE94B5B25ED

taxon LSID

lsid:zoobank.org:act:C8BB595A-E09B-4A05-8DA9-1FE94B5B25ED

treatment provided by

Felipe

scientific name

Schockaertia aprostatica
status

sp. nov.

Schockaertia aprostatica sp. n. Diez, Reygel & Artois ( Figs. 1 View Fig and 2 View Fig )

urn:lsid:zoobank.org:act:C8BB595A-E09B-4A05-8DA9-1FE94B5B25ED

Typhlo sp. 8 in Diez et al. (2023)

Material and distribution. Cuba: Observations on live animals, two serially sectioned afterwards, one of which is designated holotype ( ZMH, No. V13677 ) and the other paratype (HU, No. 854), collected in Las Sardinas (type locality) (22 June 2017); silty and very fine-grained sand, 0.5 m deep, salinity 31‰. One specimen used for molecular analyses, collected near the Hotel Guamá (October 21, 2020); silty and very fine-grained sand, 0.8 m deep, salinity 32 ‰.

Etymology. The epithet refers to the absence of a prostate vesicle.

Diagnosis. Provisionally with the same diagnosis of the genus.

Description. The animals are 0.2 mm long (n = 2), measured on sections, unpigmented, with a pair of eyes ( Figs. 1a, c View Fig and 2a View Fig : e). The syncytial and fully ciliated epidermis is 2–3 µm thick. The epidermis contains a single type of vacuole, filled with a fine-grained eosinophilic secretion ( Fig. 1c View Fig : vc). The rhabdites are globular, 0.5–1 µm in diameter, located at the apical side of the epidermis. The cilia are 4–5 µm long. Three kinds of sac-shaped glands open at the anterior body end: coarse-grained basophilic ones (stained dark blue-black) ( Fig. 1c View Fig : gl1), fine-grained basophilic ones (stained purplish) ( Fig. 1c View Fig : gl2), and fine-grained eosinophilic ones (stained brownish) ( Fig. 1c View Fig : gl3).

The pharynx ( Figs. 1a–c View Fig and 2a–d View Fig : ph) is 62–77 µm in diameter (x = 70 µm; n = 2), measured on sections, located at 50%. The prepharyngeal cavity ( Fig. 1c View Fig : ppc) is lined with a nucleated epithelium and opens to the outside through the mouth ( Figs. 1c View Fig and 2a, b View Fig : m), which is surrounded by a sphincter ( Fig. 1c View Fig : sph1). Three types of glands open in the distal half of the pharyngeal lumen: two types containing a fine-grained eosinophilic secretion (stained brownish and reddish, respectively) ( Fig. 1c View Fig : phg1 and phg3, respectively) and one containing a coarse-grained basophilic secretion (stained dark blue-black) ( Fig. 1c View Fig : phg2). The musculature of the pharynx includes a thick external layer of circular muscles ( Fig. 1c View Fig : cm1) just inside of the septum. The pharynx lumen is lined by a syncytial epithelium ( Fig. 1c View Fig : ep) and an inner circular muscle layer ( Fig. 1c View Fig : cm2). Internal longitudinal muscles are present ( Fig. 1c View Fig : ilm). Radial muscles ( Fig. 1c View Fig : rm) run between the internal and the external walls. No muscles were observed outside of the septum or around the prepharyngeal cavity.

A pair of testes ( Fig. 1 a and c View Fig : t) is located ventrally, anterior to the pharynx. The vasa deferentia form a pair of seminal vesicles caudal to the pharynx ( Figs. 1c View Fig and 2c View Fig : sv). The seminal vesicles are lined by a nucleated epithelium. Distally, the seminal vesicles narrow and open into the copulatory bulb ( Figs. 1b, c View Fig and 2d View Fig : cb). The copulatory bulb is an unarmed sac, filled with sperm (see Fig. 2d View Fig : sm) and hence functions as an unpaired seminal vesicle. It is lined with a nucleated epithelium and longitudinal muscles and enters the common genital atrium ( Figs. 1c View Fig and 2a, b View Fig : ca) dorsally. A prostate vesicle is absent. Some sperm was also observed in the common genital atrium, which could be an artefact resulting from the fixation of the specimens or residual sperm from previous copulation events.

The paired vitellaria ( Figs. 1a, c View Fig and 2c View Fig : vi) lie dorsally at each body side, between the brain ( Fig. 1c View Fig : br) and the caudal body end. Each vitellarium connects to the respective oviduct ( Fig. 1c View Fig : od) just distally to the ovary. The ovaries ( Figs. 1a, c View Fig and 2d View Fig : ov) are kidney shaped, with the oocytes proximally diminishing in diameter. The oviducts are lined by a nucleated epithelium, and open into the sac-shaped female duct. The female duct is bipartite: The proximal globular part ( Figs. 1a–c View Fig and 2a–c View Fig : fd1) is filled with sperm and lined by a thin anucleated epithelium. More distally, the female duct forms a second, smaller part: the stalk ( Figs. 1c View Fig and 2a, b View Fig : fd2). The stalk is lined by a nucleated epithelium and longitudinal muscles and opens caudally into the common genital atrium. Muscles were not observed around the oviducts or the proximal part of the female duct. The proximal part of the female duct opens to the outside through a caudal vagina ( Figs. 1c View Fig and 2c View Fig : va). The common genital atrium is lined by a low, nucleated epithelium and by longitudinal muscles. It receives fine-grained, eosinophilic glands ( Fig. 1c View Fig : eg) through its caudal wall. The common gonopore ( Figs. 1c View Fig and 2a, b View Fig : cg) is situated at 80% and is surrounded by a sphincter ( Fig. 1c View Fig : sph2).

Neotyphloplanida Willems et al., 2006 Thalassotyphloplanida Willems et al., 2006 Kytorhynchidae Rieger, 1974

Kytorhynchus Rieger, 1974

Eukytorhynchus Boyko, 1996

Kytorhynchus (Eukytorhynchus) microstylus Rieger, 1974

( Fig. 3a–d View Fig )

Kytorhynchus sp. 1 in Diez et al. (2023)

Known distribution. Beaufort, NC, USA, and Tobacco Bay, St. George, Bermuda ( Rieger, 1974).

Material and distribution. Cuba: Observations on live animals, whole mounted afterwards. Five whole mounts from Siboney (7 February 2016 and 5 June 2017) (HU XIX.2.23– XIX.2.27); fine sand with organic matter, 0.5 m deep, salinity 32‰. Three whole mounts from Bueycabón (18 November and 14 December 2017; 6 February 2018) (HU XIX.2.28– XIX.2.30), fine silty sand, 0.5 m deep, salinity 31–33‰. One whole mount from Sardinero (30 ctober 2018) (HU XIX.2.31), fine sand, 1.4 m deep, salinity 32‰. Two specimens used for molecular analyses, one from Siboney and another from Chivirico .

Remarks. Habitus and internal organisation of the specimens from Cuba ( Fig. 3a View Fig ) are as described by Rieger (1974) in the original description. The funnel-shaped stylet ( Fig. 3b, c View Fig : st, Fig. 3d View Fig ), with longitudinal folds over its entire length and distally hook shaped, is 23–43 µm long (x = 34 µm; n = 9) and 10–27 µm wide proximally (x = 17 µm; n = 9). In some specimens, the stylet is complete straight ( Fig. 3c View Fig ).

Kytorhynchus (Eukytorhynchus) yusdieli sp. n. Diez, Reygel & Artois

( Fig. 3e–g View Fig )

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Kytorhynchus sp. 2 in Diez et al. (2023)

Material and distribution. Cuba: Observations on live animals, whole mounted afterwards. One whole mount from Bueycabón (Type locality) (June 5, 2017), designated holotype ( ZMH, No. V13678 ), fine silty sand, 0.5 m deep, salinity 31‰. Four whole mounts from Sardinero (October 30, 2018 and March 18, 2021) (HU XIX.2.32– XIX.2.35), one specimen collected subtidally, fine sand, 1.4 m deep, three specimens collected subtidally, 0.5 m deep, fine sand, salinity 32‰. Four whole mounts from Embarcadero de Cayo Granma, Bahía de Santiago de Cuba (March 5, 2022) (HU XIX.2.36– XIX.2.39), sublittoral, 1 m deep, coarse and shelly sand with organic matter, salinity 35‰. One specimen used for molecular analyses, collected in Juraguá (11 May 2021); sublittoral, fine sand, 0.8 mm deep, salinity 34 ‰.

Etymology. Species dedicated to Dr. Yusdiel Torres-Cambas (Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Germany), specialist in systematics and evolution of Odonata.

Diagnosis. Species of Kytorhynchus with a funnel-shaped stylet ~ 58 µm long, ~ 47 µm wide proximally, and ~ 20 µm wide distally, with longitudinal folds over its entire length.

Description. The live specimens ( Fig. 3e View Fig ) are about 1.2 mm long, translucent, without eyes. They are slightly brownish due to the presence of parenchymal glands. The anterior body invagination ( Fig. 3e View Fig : in) is well developed, triangular and appears brown. The pharynx ( Fig. 3e View Fig : ph) is 225 µm in diameter (n = 1) and located at 70–80%.

The testes ( Fig. 3e View Fig : t) are located anterior to the pharynx. The vasa deferentia run backward and open proximally into the copulatory bulb. The copulatory bulb is located latero-caudal to the pharynx. The copulatory bulb encloses the seminal vesicle ( Fig. 3e View Fig : sv), the prostate vesicle, and the stylet. The funnel-shaped stylet ( Fig. 3e View Fig : st, f–g) is 53–62 µm long (x = 58 µm; n = 8), 34–53 µm wide proximally (x = 47 µm; n = 8), and 15–22 µm wide distally (x = 20 µm; n = 8). It shows longitudinal folds over its entire length.

The paired vitellaria run dorsally from the anterior part to the caudal body end. The globular ovaries are located caudally.

ZMH

Zoologisches Museum Hamburg

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