Marionina scintillans, Boros & Dózsa-Farkas & C, 2008

Boros, G., Dózsa-Farkas, K. & C, H-, 2008, Marionina Scintillans Sp. N., A New Enchytraeid Species (Annelida: Oligochaeta) From Hungarian Green Houses, Acta Zoologica Academiae Scientiarum Hungaricae 54 (2), pp. 113-123 : 120-122

publication ID	https://doi.org/ 10.5281/zenodo.12585208
persistent identifier	https://treatment.plazi.org/id/038A87BB-9B04-BE0A-FD80-7F89AB84EE11
treatment provided by	Felipe
scientific name	Marionina scintillans
status	sp. nov.

Treatment

Marionina scintillans View in CoL sp. n

( Figs 1–26 View Figs 1–5 View Figs 6–10 View Figs 11–16 View Figs 17–22 View Figs 23–26 )

Holotype: Ma 4, fixed cold Bouin’s fluid, whole-mounted on slide.

Type locality: green house of Budapest Zoo and Botanical Garden , in the stock of Phoenix canariensis , coll. G. BOROS, 08. 03. 2006 .

Paratypes: P. 84.1: three specimens, whole mounted together on a slide, previously fixed in cold Bouin’s fluid from the green house of Eötvös Loránd University. P. 84.2 – P.84.8 twenty-six specimens whole mounted on 7 slides, previously fixed in cold Bouin’s fluid, from the Budapest Zoo and Botanical Garden. P. 84.9 – P.84.10 eight specimens whole mounted on two slide, previously fixed in ethanol + formaldehyde, from the Budapest Zoo and Botanical Garden. P. 84.11 a worm and its flown out coelomocytes dried out and mounted on a slide in euparal from the Budapest Zoo and Botanical Garden. P. 84.12 thirty-eight specimens fixed in ethanol + formaldehyde and preserved in 70 % ethanol. P.84.13 twenty specimens fixed in hot Bouin’s fluid and preserved in 70 % ethanol all both from the Budapest Zoo and Botanical Garden. All animals were collected on 08.03.2006 and P.84.1 – P.84.6 and P.84.11 was fixed in March 2006, but P.84.7 – P.84.13 (except P.84.11) was fixed in May 2007 from the living worms of the soil samples holding in laboratory .

Etymology: scintillans (lat.) = shiny, bright. Named after the trait of coelomocytes filled with large granules, which are shining in the colours of the rainbow.

Diagnosis. Length 2.0– 2.9 mm diameter 81–119 µm (in VIII) (in vivo), segments 19–23. Chetae are straight formula: 0–0: (0),2–2. Clitellum mostly XII–2/3XIII large hyaline and granular gland cells in about 18–19 rows, ventrally absent. Two pairs of pharyngeal glands merging dorsally at 4/5 and 5/6, with well developed ventral lobes. The third pharyngeal glands absent. One pair of small secondary glands in VI. Preseptal part of nephridia consisting of funnel and nephridial canal, postseptal part elongate, twice as long as preseptal part efferent duct terminal have a conspicuous vesicle at the opening. Pre- and postclitellarly only 2–3 nephridia (paired or single) variable in segments. Most individuals showed unusual nephridial degeneration: the enlargened end of efferent duct constitute a sack which is freely moving in the body cavity. Blood vessel originates in XII, blood colourless. The dorsal anterior blood vessel bifurcation is behind the brain in III. Coelomocytes are elliptical filled with fine and crystal-like larger granules, dark in transmitted light, at the same time shining in the colours of the rainbow. Sperm funnel small, pear–shaped, collar narrower than funnel, sperm duct long and narrow coiled. Penial bulbs small (length 20–25 µm) and compact, seminal vesicle absent. Spermatheca confined to V, connected to oesophagus by short ental ducts, ectal ducts covered by small glands and one or two larger ectal gland at the orifice. Ampulla oval, or spherical when full with sperm (diameter 14–23 µm).

Description. Body colour whitish. Very small species: holotype is 2,16 mm long and 81 µm wide in VIII and 95 µm at clitellum (fixed), segments 21. Body length of paratypes 2.0– 2.9 mm, width 81–119 µm in VIII and 95–130 mm at clitellum (in vivo), length of fixed specimens 1.6–2.2 mm and the diameter 57–100 µm in VIII, 71–119 µm at clitellum. Segments 19–23. Two straight chaetae per bundle with distinct ental hook ( Fig. 1 View Figs 1–5 ), equal sized in a bundle, length increasing toward posteriorly body end, 20–22 µm long in preclitellar segments and 28–32 µm at the body end, dorsally all absent, in II and XII (at maturity) missing ventrally too. Chaetal formula: 0–0: (0),2–2. Epidermal gland cells inconspicuous. Clitellum ( Figs 3 View Figs 1–5 , 11–14 View Figs 11–16 ) in XII–2/3 XIII or XII–XIII, gland cells squared, large hyaline and granular cells, arranged in about 18–19 rows, near to penial bulb only granulocytes ( Fig. 11 View Figs 11–16 ) and ventrally absent. In living specimens the granulocytes are conspicuous ( Figs 11, 13 View Figs 11–16 ), in fixed and stained specimens the hyalocytes are better visible ( Figs 12, 14 View Figs 11–16 ). Head pore at 0/I. Brain ( Fig. 4 View Figs 1–5 ) ca 55–80 µm long and 26–32 µm wide (fix.) concave anteriorly and incised posteriorly. Two pairs of pharyngeal glands merging dorsally at 4/5 and 5/6, both with well developed ventral lobes. One pair of small (postseptal) secondary glands occurs in VI behind the septum 5/6 ventro-laterally ( Figs 6, 7 View Figs 6–10 ). The third pharyngeal glands absent. One pair of postpharyngeal bulbs present in III. Transition between oesophagus and intestine gradual, no gut appendages present. Chloragogen cells from V forming a dense layer from VII, their diameter 17–30 µm with large yellow oil body in them ( Fig. 20 View Figs 17–22 ). A longitudinal ridge of tall epithelial hyaline cells noticeable in the inner ventral wall of the intestine in XIV–XVIII, occupying mostly 1,5–2 segments ( Fig. 15 View Figs 11–16 ). Nephridia ( Fig. 5 View Figs 1–5 ) mostly unpaired, preclitellar in 6/7 and 7/8 sometimes in 8/9 or 9/10 too. Preseptal part consisting of funnel and nephridial canal, postseptal part elongate, twice as long as preseptal part. Efferent duct terminal, widen out and have a 10–12 µm wide conspicuous vesicle at the outlet ( Figs 19, 21 View Figs 17–22 ). Postclitellarly only 2–3 nephridia (paired or single) variable in segments (e.g. 15/16 and 19/20 or 14/15 and 16/17). Most individuals showed unusual nephridial degeneration. In some segments one nephridium developed normally while the other is either missing or only the enlargened end of efferent duct is present leading to its pore in front of the chaetal bundles and as a sack it is freely moving in the body cavity ( Fig. 21, 22 View Figs 17–22 ). In other cases both nephridia were reduced, sometimes asymmetrically (e.g. one of them is 20 µm, the other 37 µm). In certain segments no nephridia were present not even in a reduced form. Their distribution greatly varies, however, usually there is one nephridium in 6/7, a complete organ and a reduced “sack” in 7/8 or one sack on each side in VIII, one complete organ in 9/10 and in 15/16, one sack in XI, XIV and XVIII. However, there can be a full organ postclitellary in 13/14, one pair of organs in 16/17 or one organ in 13/14 and 15/16, and two “sacks” in XVIII.

Blood vessel originates in XII, blood colourless. The dorsal anterior blood vessel bifurcation is behind the brain in III ( Fig. 16 View Figs 11–16 ). Coelomocytes ( Figs. 2 View Figs 1–5 , 17, 18 View Figs 17–22 ) are elliptical (12–18 µm long in fixed worms), filled with fine and larger (1–3 µm long) granules, dark in transmitted light, at the same time these large crystal-like granules are shining in the colours of the rainbow especially in DIC microscope. In the interesting way these larger granules don’t lose their character when the coelomocytes dried out ( Fig. 18 View Figs 17–22 ).

Sperm funnel ( Figs 10 View Figs 6–10 , 23, 25 View Figs 23–26 ) small, 30–40 µm long and 18–19 µm wide (fix.), pear–shaped, collar narrower than funnel, spermatozoa ca. 25 µm long. Sperm duct long and narrow (ca. 3 µm wide) coiled, sometimes wound into a spiral in XII. Penial bulbs small (length 20–25 µm) and compact ca. 20 µm distance to each other ( Fig. 24 View Figs 23–26 ). Seminal vesicle absent. Spermatheca ( Figs 8, 9 View Figs 6–10 , 26 View Figs 23–26 ) confined to V, connected to oesophagus by short ental ducts. Ectal pores in intersegmental furrow of 4/5, ectal ducts ca. 16–25 µm long and 7–8 µm wide (in fixed specimens) covered by small glands and accompanied by one or two larger ectal gland at the orifice. The ectal glands are almost as wide as the ectal duct diameter. Ampulla oval, or spherical when full with sperm (diameter 14–23 µm). One egg mature at a time .

Remarks. The new species differs from all Marionina species by having 2 (rarely one) chaetae in all ventral bundles while they are missing in all dorsal bundles, the absence of the third pharyngeal glands and the possession of a pair of small postseptal (secondary) pharyngeal glands in VI close to 5/6 and the peculiar nephridial degeneration. The closest relative of Marionina scintillans appears to be M. seminuda XIE et ROTA, 2000 and M. subterranea (KNÖLLNER, 1935) . M. subterranea , however, larger (25 segments, 4 mm long), ventral chaetae are present in II, the first and second pharyngeal glands do not have ventral lobes and the spermatheca bears glands only at the ectal pores. M. seminuda was described from China (XIE & ROTA 2000) and a year later from New Zealand (ROTA & MANCONI 2001). It is possible that the latter is a new species because some characters differ from the types (e.g. the size distribution of chaetae, distribution of preclitellar nephridia, absence of seminal vesicle and the coelomocytes were not seen in the New Zealand specimens). The habitats were also considerably different. In China it exists in moist to wet soil along a river while specimens from New Zealand were collected from Heterorotula sp. sponge living at 127–145 meter depth in a lake. Marionina scintillans sp. n. is similar in many characters, namely the setal formula, the anterior bifurcation of dorsal blood vessel behind the pharynx, the form of the brain (incised posteriorly) and the spermatheca, the well visible postpharyngeal bulbs in the III, and the granular and hyalin clitellar glands arranged in approximately 18 transverse rows, to both variations of M. seminuda . In the new species the glandular cells of the clitellum are absent ventrally but this character was not mentioned in the description of M. seminuda . M. scintillans also differs in some further characters from M. seminuda from China and M. seminuda from New Zealand as summarized in Table 1.

Further two small Marionina species ( M. eleonorae ROTA, 1995 and M. praeclitellochaeta NIELSEN et CHRISTENSEN, 1963 ) also have two pairs of pharyngeal glands only but neither of them have postseptal glands in VI. Moreover in M. eleonorae the pharyngeal glands are free dorsally ( ROTA 1995) while those of the M. scintillans are fused. Furthermore, M. eleonorae has two chaetae in all dorsal bundles and the dorsal blood vessel originates in VIII ( ROTA 1995). Similarly, M. praeclitellochaeta only bears ventral chaetae but only from II to VI ( NIELSEN & CHRISTENSEN 1963).

Acknowledgements – This study is supported by the Hungarian Scientific Research Found (OTKA T034864 and T049635). We thank Dr. ILMA BOGSCH, Director of the Budapest Zoo and Botanical Garden and Dr. LÁSZLÓ ORLÓCZY and Dr. ISTVÁN ISÉPY, Directors of the ELTE Botanical Garden for making the collections possible.