Pseudoamphisiella elongata, Li & Song & Al-Rasheid & Warren & Li & Xu & Shao, 2010
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publication ID |
https://doi.org/ 10.1111/j.1096-3642.2009.00546.x |
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DOI |
https://doi.org/10.5281/zenodo.10545457 |
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persistent identifier |
https://treatment.plazi.org/id/03D45727-9602-AB4F-FCD0-FC4BFE2A65D6 |
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treatment provided by |
Valdenar |
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scientific name |
Pseudoamphisiella elongata |
| status |
sp. nov. |
PSEUDOAMPHISIELLA ELONGATA SP. NOV.
( FIGS 1 View Figure 1 , 2 View Figure 2 ; TABLE 1)
Diagnosis: Elongated marine Pseudoamphisiella , in vivo 160–240 Mm ¥ 30–40 Mm, with conspicuous extrusomes within outer alveolar layer, 25–44 macronuclear nodules, and 6–17 micronuclei. On average, 44 adoral membranelles; two buccal and three frontal cirri; one row of 16–21 strong transverse cirri that Data based on protargol-stained specimens. extends anteriorly almost to the proximal end of the adoral zone of membranelles (AZM); two or three fine pretransverse cirri; two widely separated ventral rows comprising between 16 and 18 cirri, respectively; 26–45 and 28–36 cirri in left and right marginal rows, respectively; six or seven caudal cirri; six or seven dorsal kineties.
Type locality: Mariculture waters of the Yellow Sea coast at Qingdao, China (36°08′N; 120°43′E) GoogleMaps .
Type specimens: One holotype slide of protargolimpregnated specimens is deposited in the Natural History Museum , London , UK, with registration no. 2008:5:14:1. One paratype slide is deposited in the Laboratory of Protozoology , Ocean University of China ( OUC), Qingdao, China, registration no. LLQ- 20071127 -01 .
Etymology: The species name elongata (Latin adjective, meaning elongated or stretched) refers to the elongate body shape.
Description: Cells are mostly 200 Mm ¥ 30 Mm in vivo, with a length to width ratio ranging roughly from 5: 1 to 7: 1. Body elongate, slender, and more or less cephalized; posterior end only slightly narrowed ( Figs 1A, B View Figure 1 ; 2A, D View Figure 2 ). Cell flexible and slightly contractile, making it a little shorter when stationary than when moving ( Fig. 2B, G View Figure 2 ). Body margins generally straight and parallel. Outline shape variable, depending on nutritional status; starving individuals were widest in the buccal field ( Figs 1C View Figure 1 , 2C View Figure 2 ). Dorsoventrally flattened about 1: 3 ( Fig. 2E View Figure 2 ). Buccal field characteristically short and narrow, about 15% of body length in vivo ( Fig. 1A, B View Figure 1 ).
Pellicular alveolar layer clearly observed in vivo, about 3–4-Mm thick, with densely arranged rodshaped extrusomes perpendicular to pellicle ( Figs 1E View Figure 1 arrows, 2B arrows, 2E inset, 2F). When viewed dorsally, the alveolar layer is seen to have an irregular polygonal structure ( Figs 1D View Figure 1 , 2H View Figure 2 ).
Cytoplasm colourless, whereas ingested food (e.g. pennate diatoms) usually makes the cell opaque when observed at lower magnifications ( Fig. 2A, B, D View Figure 2 ). Contractile vacuole not observed, possibly absent. Between 25 and 44 macronuclear nodules (Ma), spherical to slightly oval in shape; between 6 and 17 micronuclei (Mi), spherical, about 3 Mm in diameter ( Figs 1G View Figure 1 , 2N View Figure 2 ).
Locomotion is typically achieved by rapid and continuous crawling on debris or on the bottom of the Petri dish. Occasionally P. elongata sp. nov. specimens remain still for long periods, until they are disturbed.
The distal end of the AZM curves posteriorly onto the right side towards the buccal cavity. The longest membranelle base is about 12-Mm wide, with those in the distal (right) portion of the AZM distinctly shorter than those in proximal (left) portion. The paroral membrane (PM) is shorter than the endoral membrane (EM), but they do not cross each other ( Figs 1F View Figure 1 , 2M View Figure 2 ).
Most of the somatic cirri are relatively fine and are about 15-Mm long. Three slightly enlarged frontal cirri (FC) are situated along the distal portion of the AZM. The posteriormost FC are positioned between the anterior end of the right marginal row and the distal end of the AZM ( Figs 1F View Figure 1 , 2M View Figure 2 arrows). Two mediumsized buccal cirri (BC) are located between the PM and the EM (arrows in Fig. 1F View Figure 1 ). The left midventral row is long, starting near the undulating membranes (UM) and terminating at the posterior fifth of the body length ( Figs 1F View Figure 1 , 2N View Figure 2 ). The right midventral row (RMVR) is composed of densely arranged cirri, anteriorly terminating around the distal end of the AZM, and extending posteriorly to between three-fifths and two-thirds of the body length ( Figs 1F View Figure 1 , 2K View Figure 2 arrow).
About 20 highly developed transverse cirri (TC), ~20 Mm long, are arranged in a J-shaped row that extends anteriorly to about the level of the cytostome ( Figs 1F View Figure 1 , 2N View Figure 2 ). Two fine pretransverse cirri (PTC) are situated close to the posterior end of the TC ( Figs 1F View Figure 1 arrowheads, 2L arrows). The left and right marginal rows (LMR, RMR) have 26–45 and 28–36 cirri, respectively; the ends of the marginal rows are confluent with caudal cirri at the posterior end of cell, and hence it is difficult to distinguish where the marginal rows terminate ( Figs 1F View Figure 1 , 2J View Figure 2 arrow). Strong fibrils are associated with almost all of the somatic cirri, as revealed by protargol impregnation ( Figs 1F View Figure 1 , 2N View Figure 2 ).
Six or seven dorsal kineties (DK) extend along the whole length of the body, with dorsal cilia of about 5-Mm long ( Figs 1G View Figure 1 , 2I View Figure 2 arrows).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.