Paraturbanella levantia, Hummon, William D., 2011

Hummon, William D., 2011, Marine Gastrotricha of the Near East: 1. Fourteen new species of Macrodasyida and a redescription of Dactylopodola agadasys Hochberg, 2003, ZooKeys 94, pp. 1-59 : 34-35

Paraturbanella levantia sp. n. Figure 17

Paraturbanella EgyA Hummon (2001, 2004, 2007, 2009) [E Med & Red Seas Database].

Paraturbanella levantina Todaro et al. (2003: Appx. I, listed as nomen nudum that was reported in a CD "Global Data Base for Marine Gastrotricha" Hummon, 2001*)

Diagnosis:

Adult Lt 657 µm; PhJIn at U23. Body elongate, slender; mouth a narrow outwardly rolled protrusion, head with a band of circumcephalic cilia at U03 and prominent pestle organs at U04, but lacking lateral lobes; neck constriction lacking, body sides parallel over most of their length, thinning gradually to the caudal base; caudum is slightly cleft, incised from its tips to U97; medial cone usually absent. Glands inconspicuous, ca. 28 per side. TbA 8 per side, the shortest one inserting on the medial edge, occur on fleshy hands that insert at U11; TbL absent; TbD 7 per side at U27-U84 and TbV 14 per side at U29-U88, all in the intestinal region, of similar size and spacing; ‘dohrni’ [ Seitenfüsschen] tubes 2 per side, posteriolaterally directed (L longer tube =20 µm, shorter =15 µm), inserting ventrolaterally just behind the fleshy hands at U12; TbP 8 per side, the outermost being the longest and thickest, the others being shorter, with none occurring on the lateral or leading edges of the lobes. Locomotor ciliature: 2 longitudinal bands run from the pestle organs back and join behind the level of the anus. Mouth terminal, breadth narrow; buccal cavity small, deep, vaseshaped; walls of medium cuticularization; basal pharyngeal pores large and conspicuous; intestine narrows gradually front to rear; anus is ventral at U93. Hermaphroditic, protandrous to simultaneous; paired testes extend rearward from just behind the PhJIn, their vasa deferentia recurving to the fore and exiting at about U31; small developing ova occur bilaterally in the mid-gut region; frontal and caudal organs not seen.

Description:

Adult Lt 635-657 µm; L to PhJIn 155-163 µm at U26-U23 (Fig. 17). Body elongate, slender; mouth a narrow outwardly rolled protrusion, head with a band of circumcephalic cilia at U03 and prominent pestle organs at U04, but lacking lateral lobes; neck constriction lacking, body sides parallel over most of their length, thinning gradually to the caudal base; caudum is slightly cleft, incised from its tips to U97; medial cone is usually absent. Widths at narrowed mouth /pestle organs /PhJIn /mid-trunk /furcal base, tips, and their locations along the body length are: 18 /31 /38 /44 /18, 30 µm at U02 /U04 /U23 /U58 /U97, U100. Epidermal glands ca. 28 per side, small (2-5 µm diameter), are distributed along the lateral body margins, but appear inconspicuous.

Adhesive tubes: TbA 8 per side (L 5-9 µm), the shortest one inserting on the medial most edge, occur on fleshy hands that insert at U11; TbL absent; TbD 7 per side (L 11-14 µm) from U27 to U84 and TbV 14 per side (L also 11-14 µm) from U29 to U88, all of similar size and spacing in the intestinal region; ‘dohrni’ [ Seitenfüsschen] tubes 2 per side, posteriolaterally directed (L longer tube 20 µm, shorter 15 µm), inserting ventrolaterally immediately behind the fleshy hands at U12; TbP 8 per side, the outermost being the longest and thickest (L 14 µm), the others being shorter (L 3-9 µm), none occurring on the lateral or leading edges of the lobes.

Ciliation: Head protrusion has sensory hairs (L 11-30 µm) laterally and a circumcephalic band of cilia (L 14 µm) at U03; other sensory hairs (L 20-30 µm) occur on the trunk in lateral, dorsolateral and dorsal columns, with 14/14/18 per side. Ventral locomotor cilia (L=8 µm) flow from the circumcephalic band rearward in two longitudinal bands that trace the lateral body margins, joining again behind the level of the anus.

Digestive tract: Mouth terminal, narrow (8 µm diameter); buccal cavity small, deep, vaseshaped; walls of medium cuticularization; basal pharyngeal pores are large and conspicuous, but lack pharyngeal knobs; intestine broadest in front, narrowing gradually to the rear, with a bulge at the level of the ventral anus, U93.

Reproductive tract: Hermaphroditic, protandrous to simultaneous; paired testes extend rearward from just behind the PhJIn, their vasa deferentia recurving from the rear to the fore and exiting behind together at U31; small developing ova (61 × 13 and 41 × 8 µm) occur bilaterally in the mid-gut region; neither frontal nor caudal organs were seen.

Ecology:

Sparse (less than 10% of samples) in frequency of occurrence, rare to scarce (fewer than 1 to 3-5% of a sample) in abundance; sublittoral in very fine to medium fine, medium-well sorted silicious or carbonate sand at 0.53 m depth, occasionally in fine to coarse, poorly sorted sand at 6 m depth near the bases of beachrock slabs.

Geographical distribution:

MED SEA:CYPRUS: {Coral Bay [video]}; EGYPT: {^Bir Mesud (31°14'N, 29°58'E) [video], Cleopatra Beach [video], Green Beach, Hannoville, Mamura [4-videos]}; ISRAEL: {Palmachim N [video]}.

Remarks:

There are eight video sequences of Paraturbanella levantia sp. n., all from the eastern Mediterranean Sea in Cyprus, Egypt and Israel. Five of these are available as MPEG 2 (and MPEG 1) from Hummon (2009): #975 a mature Lectotype adult of Lt=657 µm (LPh=168 µm), collected in April 1994 from Bir Mesud, near Alexandria, Egypt; #976 a mature adult of Lt=635 µm (LPh=163 µm) from Coral Bay, Cyprus; #974 a subadult of Lt=400 µm (LPh=138 µm) from Cleopatra Beach, in Alexandria; #972 a subadult of Lt=335 µm (LPh=127 µm) from Mamura, near Alexandria; and the other, #971 a juvenile of Lt=211 µm (LPh=96 µm) also from Mamura. The Cleopatra specimen alone showed a caudal cone; others had an associated gland, but no protruding cone. Specimens often bear a variety of small diatoms internally. [*Note: some proposed species names were included in the prototype CD, referred to by Todaro et al. 2003, but were expurgated from the CD before it was made available to all attendees at the 11th International Meiofauna Conference of 2001 in Boston.]

Etymology:

Levantia is named after the eastern Mediterranean region in which it was first found.

Taxonomic affinities:

Paraturbanella levantia sp. n. is the only species in the genus to have a narrowly protruding outwardly rolled mouth, prominent pestle organs at U04, and a PhJIn at U26-U23, which also has TbA 8 per side, the medial tube shorter than the others; TbL absent; TbD 7 per side and TbV 14 per side, all in the intestinal region; TbP 8 per side, the outer being the longest and thickest; ‘dohrni’ [ Seitenfüsschen] tubes 2 per side; but usually no caudal cone. Paraturbanella levantia sp. n., alone in the genus has both TbD and TbV, but lacks TbL.