Haplophallonella irenae, Camacho & Brancelj & Dorda & Casado & Rey, 2016
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publication ID |
https://doi.org/ 10.1080/00222933.2016.1210260 |
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persistent identifier |
https://treatment.plazi.org/id/03D787C8-8E79-8A5D-FE1E-FE26FDAF1F1A |
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treatment provided by |
Felipe |
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scientific name |
Haplophallonella irenae |
| status |
sp. nov. |
Haplophallonella irenae sp. nov.
( Figures 1 – 3 View Figure 1 View Figure 2 View Figure 3 ).
Material examined
Type locality. Dry channel of the river Oued Douar near village Totous, Tibesti area ( Chad) (19°26 ′ 22 ′′ N, 17°31 ′ 47 ′′ E, altitude 585 m; 14 March 2014, (one male, one female and two juveniles); collected by A GoogleMaps . Brancelj GoogleMaps . The holotype ( MNCN 20.04 View Materials /10148) is the male and the allotype the female ( MNCN 20.04 View Materials /10149) . Details of the descriptions are based on adult specimens. All specimens collected belong to the type series, two morphotypes, together with DNA extractions from two juveniles used for molecular analysis, two DNA types ( MNCN /ADN 29986 and MNCN /ADN 29987) .
Description
Body. Total length of holotype 0.95 mm, allotype 0.92 mm. Body elongated, segments widening towards posterior end; approximately 9 times as long as wide. Head a little longer than wide. Pleotelson with 1 medium-sized plumose ventral seta on each side. All drawings are of the holotype (male) except for the female Th VIII, and one figure of the labrum that belongs to the allotype (female).
Antennule ( Figure 2a View Figure 2 ). Six-segmented; length of first 3 segments 1.5 times longer than other 3 segments combined; sixth segment as long as the third segment but is the thinnest, 3 times thinner than the first 4 segments; inner flagellum almost square; setation as in Figure 2a View Figure 2 ; segment three with 3 smooth setae; segment five with 3 terminal aesthetascs, similar in size; sixth segment with 3 aesthetascs, each of a different size. A.I longer than antenna.
Antenna ( Figure 2b View Figure 2 ). Five-segmented; as long as the first 4 segments of A.I; first two segments shortest; last 2 segments similar in size and slightly longer than the third; last segment with 3 setae, o1of which is plumose; setal formula: 0/0+1/1+0/1+0/3(1).
Labrum of the holotype ( Figure 2c View Figure 2 ). Cleft, distal edge divided into 2 equally developed parts with convex contour; with 12 main teeth, 6 in each part, and 3 more lateral teeth at each side; the central teeth, 4 in each part, are not triangular, but are slightly rectangular distal edge.
Labrum of the allotype ( Figure 2d View Figure 2 ). Similar to the male but with fewer teeth, with 9 main teeth (4 and 5 in each part) and only 2 more additional lateral teeth at each side.
Mandible ( Figure 2e View Figure 2 ). Pars incisiva with 4 teeth on distal part and without tooth on the ventral edge; pars molaris with 5 claws, 1 distal group of 3 claws with subdistal small spines and a second group of 2 smooth joined proximal claws with a large number of fine hairs; mandibular palp 1-segmented, with a distal seta as long as the pars incisiva in length.
Maxillule ( Figure 2f View Figure 2 ). Proximal endite with 3 long claws with a small number of long setules and an additional small and smooth claw; distal endite with 5 claws, all smooth, except second 1 with fine long setules, the 4 distal teeth are grouped in the terminal part of the Mx.I, with 3 subterminal smooth setae of different size on outer distal margin.
Maxilla ( Figure 2g View Figure 2 ). Two-segmented; basal segment almost 3 times smaller than the second segment, with 2 smooth setae; second segment wide, twice as long as wide with 13 setae (3+1 on median region, 5 subterminally and 4 terminally) and 1 terminal strong claw with small setules.
Thoracopods I to VII ( Figure 3a–g View Figure 3 ). Well-developed, length gradually increasing from I to III, last 5 similar in size; epipod absent on Th I, present on Th II to VII, almost half the length of basipod; basipod with 1 smooth seta at distal inner corner on Th I to VII. Exopod 2-segmented, a little shorter than the 3 first segments of
endopod on Th I to III ( Figure 3a, c View Figure 3 ) and Th VI and Th VII ( Figure 3f, g View Figure 3 ), and similar in size on Th IV and V ( Figure 3d, e View Figure 3 ); with 2 terminal setae on segment two, 1 barbed and 1 plumose, similar in size on Th I and different size on the rest of exopods of Th II toVII, with 2 setae on the first segment, 1 barbed seta on all Ths and 1 short, plumose seta on Th I to V and 1 smooth seta on Th VI and VII. Endopods 4- segmented, the first segment almost half as long as segments two and three, similar in length in all thoracopods; fourth segments very small (with 2, similar claws and 1 smooth seta on Th I and 1 barbed claw and 1 smooth seta on the rest of Ths); all setae on segments one to three are smooth except the plumose setae at the distal outer corner of segments two and three. Setal formula of endopods: Th I, 1+0/1+1/0 +1/3(1); Th II – VII, 0+0/0+1/0+1/2(1).
Male thoracopod VIII ( Figure 2h–k View Figure 2 ). Massive, almost square; well-developed basal region of the penial complex, small penial region supports 2 lobes: inner lobe (I. Lb.) and dentate lobe (D. Lb.); oval inner lobe as a projection of basal region similar to dentate lobe which has only 3 teeth on distal end; outer lobe (O. Lb.) fused with basipod, distal end very short and not exceeding distal end of basipod (Bsp); endopod completely reduced, without observed setae; exopod (Exp.) located on distal face of basipod, fully integrated into it, curved like a double-headed claw; basipod roughly trapezoidal, with a strong seta in the distal corner.
Female thoracopod VIII of the allotype ( Figure 3h View Figure 3 ). Very reduced, appears in ventral view as 2 processes almost triangular in shape, with rounded distal part.
Pleopods. Absent.
Uropods ( Figure 2l View Figure 2 ). Sympod length 5 times as long as wide, twice as long as endopod and exopod, which are similar in size; 3 barbed spines of similar size and a distal one, one-third longer than the others, occupying distal third of sympod; endopod with long apical spine with setules and 4 setae, 2 terminal (1 barbed and 1 plumose) and 2 more latero-external and dorsal plumose setae of different length, with 4 groups of strong ctenidia on dorsal face; exopod has 2 terminal barbed setae and 1 basal plumose seta.
Pleotelson ( Figure 3i View Figure 3 ). With 1 small, plumose ventral seta on either side near base of the furca. Anal operculum not protruded.
Furca ( Figure 3i View Figure 3 ). Almost square, with 4 barbed spines, the 2 distal ones 1/3 longer than the other 2, which are similar in length; at the base of the spines is a membrane with setules at the distal edge; the dorsal side of furcal rami armed with 2 plumose setae of different lengths, which is characteristic for the family Parabathynellidae .
Etymology
The species, ‘ irenae ’ (female gender, adjective), is named as a tribute ‘ in memoriam ’ to Irena Rejec Brancelj, very recently deceased wife of A. Brancelj.
Remarks
There are only two genera, Habrobathynella Schminke, 1973 and Haplophallonella , with a labrum similar to that of the new species, cleft in half and with a different number of teeth on each side. Habrobathynella has Mx.II with two segments and distal claws, like the new species described in this paper, but has A.II with two segments and Md with a proximal tooth, while the new species from Chad has five antennal segments and lacks the mandibular proximal tooth. These characteristics are consistent with the description of Haplophallonella , to which it could be assigned also due to having a male Th VIII with a merged outer lobe in the basipod, with the exopod located in the distal side of the basipod showing a claw shape, as well as the total absence of the endopod in it.
Differences between the type species H. heterodonta and H. irenae sp. nov. are shown in Table 1. The two species are of a similar size, less than a millimetre. The new species has thicker and shorter antennular segments compared to H. heterodonta , and the setation of the segments is different. The most notable trait is the lack of plumose setae in segment three, and the presence of three aesthetascs in the last two segments in H. irenae sp. nov. It also has fewer teeth in the labrum than the type species does, and a single distal claw in the maxilla; the setation of thoracopods I to VII is different between the species, too. There are two plumose setae in the exopod of the new species and only one in the type species, which also lacks the small plumose seta in segment three of the endopod, but it is present in the new species. Segment four of the endopod is smaller in the new species than in the type species, and the same is true for the rest of the segments; H. heterodonta has the exopod and endopod of all thoracopods with the same length, while in H. irenae sp. nov. both rami are similar only in thoracopods III to V, while the exopod is shorter than the endopod in the rest of the thoracopods. The male thoracopod VIII is almost square in the new species and not as rectangular as in the type species: it has the exopod ending in two tips and does not resemble a claw as in the type species; the inner lobe in the new species is oval with a projection in the basal region, similar to the dentate lobe, but it is shorter in the type species and is almost covered by it, and with two or three teeth in both species; the outer lobe is merged with the basipod in both species: also in both species the endopod is missing; the basipod is trapezoidal and with a long seta. The female thoracopod VIII is elongated in the type species and almost triangular in the new species. Haplophallonella irenae sp. nov. has three plumose setae in the endopod of the uropod, while there are only two in the type species. Also, there is only one basal plumose seta in the exopod that is missing in the type species. The furcal rami are slightly more square than rectangular in the new species.
| MNCN |
Museo Nacional de Ciencias Naturales |
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