Notobathynella octocamura, Camacho & Hancock, 2010

Camacho, A. I. & Hancock, P., 2010, First record of Syncarida from Queensland, Australia, with description of two new species of Notobathynella Schminke, 1973 (Crustacea, Bathynellacea, Parabathynellidae), Journal of Natural History 45 (1 - 2), pp. 113-135 : 114-124

publication ID	https://doi.org/ 10.1080/00222933.2010.520824
persistent identifier	https://treatment.plazi.org/id/FA578792-2653-C707-FE2D-36B7FD1DFBD5
treatment provided by	Felipe
scientific name	Notobathynella octocamura
status	sp. nov.

Treatment

Notobathynella octocamura sp. nov.

( Figures 1–3 View Figure 1 View Figure 2 View Figure 3 )

Material examined

Type locality. Department of Natural Resources monitoring piezometer number 13700234A, 19 May 2004, in alluvial aquifer beneath Yellow Waters Creek floodplain near Bundaberg, Queensland, Australia; 10 males, 17 females and one juvenile were collected.

Other locations. Department of Natural Resources monitoring piezometer number 13700234B, 18 May 2004, in alluvial aquifer beneath Yellow Waters Creek floodplain near Bundaberg (one female) and Piezometer 13700067, 20 May 2006, in alluvial aquifer beneath Elliott River, near Bundaberg, Queensland, Australia (five males and five females were collected) .

Details of the descriptions are based on all adult specimens, 15 males and 23 females. The holotype is a male and the allotype is a female. The type series contains 36 additional specimens (14 males and 22 females): holotype MNCN20.04 View Materials / 8229, allotype MNCN20.04 View Materials / 8230 and type series MNCN20.04 View Materials / 8231.

Description

Body. Total length of holotype (male) 1.96 mm and allotype (female) 2.7 mm. Largest male total length 1.97 mm, smallest 1.50 mm. Longest female 2.7 mm, smallest 1.46 mm. Body elongated, segments slightly widening towards posterior end; approximately nine times as long as wide. Head 1.2 times long as wide. Pleotelson with one small barbed ventral seta on either side. All drawings are of the holotype except for female Th VIII.

Antennule ( Figure 1A View Figure 1 ). Eight-segmented; no sexual dimorphism; length of first three segments similar to other four segments; segment seven smaller than others; inner flagellum almost rectangular; fourth and fifth segments similar in size; setation as in Figure 1A View Figure 1 ; segment three with six setae; segment five with two terminal aesthetascs, and sixth and seventh with three aesthetascs each.

Antenna ( Figure 1B View Figure 1 ). Five-segmented; half the length of the A.I.; first two segments are shortest, third segment twice as long as second, and last two segments almost similar in size, the last a bit longer than the previous one and with five setae, one of which is plumose; fourth segment with inner and outer seta; setal formula: 0 / 0 / 1+0 / 1+1 / 5(1).

Labrum ( Figure 1C View Figure 1 ). Slightly concave with eight main teeth and 10 lateral teeth at each side. Ventral surface with several rows of fine spinules and two tooth-like protrusions on both sides.

Female labrum of the allotype ( Figure 1D View Figure 1 ). Slightly concave with nine main teeth and nine lateral teeth at each side. Ventral surface with several rows of fine spinules and with five or six tooth-like protusions on both sides.

Mandible ( Figure 1E,F View Figure 1 ). With pars incisiva with five well-developed teeth and triangular small tooth of ventral edge; pars molaris with seven claws, five being strong with subdistal small spines and two small joined proximal claws with a large number of fine hairs; the distal seta of the mandibular palp does not exceed pars incisiva in length.

(ventral view); (F) thoracopod VIII female (dorsal view); (G) pleotelson and furcal rami (dorsal view); (H) uropod (latero-external view); (I) endopod of uropod female allotype (latero-external view). Scale bar in mm. Abbreviations: D. Lb, dentate lobe; I. Lb, inner lobe; O. Lb, outer lobe; Bsp, basipod; Endp, endopod; Exp, exopod.

Female mandible of the allotype ( Figure 1G View Figure 1 ). With pars incisiva similar to the holotype; pars molaris with nine claws, seven being strong with subdistal small spines and two small joined proximal teeth with a large number of fine hairs.

Maxillule ( Figure 1H View Figure 1 ). Proximal endite with four long serrulate claws; distal endite with eight claws: two smooth with one apical and one subapical, and the other six with denticles and fine long setules and three subterminal smooth setae on outer distal margin.

Maxilla ( Figure 1I View Figure 1 ). Four-segmented, segment three elongated and fourth very small; setal formula 4, 4+1, 16, 6.

Thoracopods I–VII ( Figure 2A–G View Figure 2 ). Well developed, length gradually increasing from I to IV, last four similar in size; epipod on I to VII small, measuring less than half length of basipod; basipod with one smooth seta at distal inner corner in Th I, II and VI, VII and with two setae in Th III to V. Exopod shorter than endopod on Th I to III and similar on Th IV to VII and with the following numbers of segments: 3-4-4- 5-5-4-4; each segment with two barbed setae (with one group of ctenidia at base of inner setae) except the last segment, which has a plumose outer seta in Th I to VI, a short, barbed seta in the Th VII; endopod four-segmented with a small first segment longer second and third segments equal in length, and a fourth segment that is small (with two barbed, similar claws and two or three smooth setae). A ll inner setae on segments are smooth and outer setae of first, second and third segment of Th I to VII are plumose. Thoracopod endopod setal formula: Th I, 4+1 / 4+1 / 2+1 / 4(2); Th II, 2+1 / 4+2 / 2+1 / 5(3); Th III, 2+1 / 4+2 / 2+1 / 5(3); Th IV, V, 1+1 / 3+2 / 2+1 / 4(2); Th VI, 1+1 / 2+2 / 1+1 / 4(2); Th VII, 1+1 / 2+1 / 1+1 / 4(2).

Allotype (female) exopod shorter than endopod on Th I to III and similar on Th IV to VII and with the following numbers of segments: 3-4-4-5-5-5-4. Setal formula of the endopods of thoracopods: Th I, 3+1 / 4+1 / 2+1 / 4(2); Th II, 2+1 / 4+2 / 3+1 / 5(3); Th III, 2+1 / 4+2 / 2+2 / 5(3); Th IV, 2+1 / 4+2 / 2+1 / 5(3); Th V, 1+1 / 3+1 / 2+1 / 5(3); Th VI, 1+1 / 3+2 / 2+1 / 4(2); Th VII, 1+1 / 3+2 / 1+1 / 4(2).

Thoracopod VIII male ( Figure 3A View Figure 3 to D). Almost square; basal region of the penial complex supports three lobes: inner lobe (I. Lb.), outer lobe (O. Lb.) and dentate lobe (D. Lb.); subtriangular inner lobe completely integrated into the basal region; outer lobe covers at the end of the inner lobe, and does not exceed the end of the external side of the basipod (Bsp); dentate lobe is bigger than inner lobe and has many denticles; endopod (Endp.) very long, almost four times longer than exopod with two smooth terminal setae; exopod (Exp.) small and with one seta; basipod trapezoidal in the external face, in the internal side with a seta above its outer distal corner and with a crest-like protuberance.

Thoracopod female VIII ( Figure 3E,F View Figure 3 ). Small, rounded with one segment with one small bidentate tooth.

First pleopods. Absent.

Uropod ( Figure 3H View Figure 3 ). Sympod four times as long as wide, a bit longer than endopod and shorter than exopod; with nine barbed spines of similar size, and one more distal spine 2.3 times longer than others; endopod much shorter than exopod, with one spinous projection and three groups of ctenidia in the inner margin, one strong spine and a “claw-like” appendage on distal part, two plumose setae near inner margin, one basal and one subterminal, that exceed the distal end of endopod, and two barbed terminal setae of different length; exopod has six barbed setae and six groups of ctenidia in the inner margin.

Uropod female ( Figure 3I View Figure 3 ). Sympod with 10 barbed spines of similar size, and one more distal spine 2.3 times longer than others; endopod shorter than exopod, with four small spinous projections and one strong spine on the distal part, two plumose setae near inner margin, one basal and one subterminal, that exceed the distal end of endopod, and two barbed terminal setae of different length.

Pleotelson ( Figure 3G View Figure 3 ). With one small, plumose ventral seta on either side near the base of the furca. Anal operculum slightly convex, protruded.

Furca ( Figure 3G View Figure 3 ). Rectangular, twice as long as wide, with 12 or 13 barbed spines (the two terminal ones longer and thicker); two unequal dorsal plumose setae, that does not exceed the distal end of terminal spines; with a smal lateral furcal organ.

Variability

The number of spines on the furca varies from 10 to 14, the sympod of the uropod 10 to 12 spines, the endopod of the uropod two to five spines. There is also variation in the number of exopodal segments of Th I–VII (3-3, 4-3, 4-4, 5-4, 5-4, 5-4) and setae on different endopodal segments of endopods of some thoracopods of males and females. The setal formula is: Th I, 3,4+1 / 3,4+1 / 2,3+1 / 4,5(2,3); Th II, 2+1 / 3,5+2 / 1,3+1 / 4,5(2,3); Th III, 1,2+1 / 2,4+1,2 / 1,3+1,2 / 4,5(2,3); Th IV, 1,2+1 / 2,4+1,2 / 1,2+1 / 4,5(2,3); Th V, 1+1 / 2,4+1,2 / 1,2+1 / 4,5(2,3); Th VI, 1+1 / 2,3+1,2 / 1,2+0,1 / 4(2); Th VII, 1+1 / 2,4+1,2 / 0,1+0,1 / 4(2).

Etymology

The species name means “eight-hooked” and refers to the eight claws on the distal endite of the maxillule; “ octocamura ” is an adjective.

Remarks

The eight claws on the distal endite of the maxillule distinguish Notobathynella octocamura sp. nov. from other members of the genus ( Table 2). Billibathynella humphreysi Cho, 2005 and Montanabathynella salish Camacho et al., 2009 are the only other parabathynellid species known to have more than seven claws on the distal endite of the Mx I (ten and nine, respectively) ( Camacho, Stanford and Newell 2009).

N. remota N. tasmaniana N. williamsi N. chiltoni N. hineoneae N. longipes N. lemurum

N. octocamura sp. nov. N. pentatrichion sp. nov.

Antennule

N. segment 7 7 7 7 7 7 6

N. aesthet. seg.5 2 1 2 2 2 2 3

Antenna

N. segs 6 5 5 5 5 5 5

Setal formula 0 / 0 / 1 / 2 / 0 / 6(1) 0 / 0 / 1 / 2 / 4(1) 0 / 0 / 1 / 2 / 4(1) 0 / 0 / 1 / 2 / 4(1) 0 / 0 / 1 / 2 / 4(1) 0 / 0 / 1 / 2 / 3(1) 0 / 0 / 1 / 2 / 3(1) Labrum

N. teeth 5+10+5 2+12+2 5+8+5 7+8+7 5+8+5 3+8+3 1+12+1 Mandible

N. teeth

pars incisiva 5 5 4 4 4 4 6

pars molaris 8 9 7 7 8 9–10 6–7 Maxillule

N. claws

distal endite 7 7 7 7 7 7 6

Maxilla

setal formula 4-5-10-8 3-6-9-9 3-5-12-8 3-5-13-8 3-6-12-8 3-6-11-8 3-4+1-1+16?

5 0 / 0 / 1 / 2 / 5(1)

5 0 / 0 / 1 / 2 / 4(1)

9–10+8+9–10 7–8+8+7–8

7–9

4-4+1-16-6

7–10

3-4+1-14-6

Thoracopod I

epipod A P P P P P P

Thoracopods I–VII

N. sgt.exp. 2-3-4-4-4-4-3 2-2-3-3-3-3-3 2-3-3,4-3,4- 1-2-3-3-3-2-2 1-3-3-3-3-3-3 2-3-3-3-3-3-2 2-3-3,4-3,4- 3,4-3-3 3,4-3-2,3

3-3,4-3,4-4,5- 4,5-4,5-4

1,3-3,4-3,4-3,4- 3,5-3,4-3,4

Uropod

N. spines 10 –I 10 –H 10–12 –I 7 –I 11- I 6–7 –I 11-13-H 10-12-I symp.

N. setae 4 2 4 4 4 4 3 6 exopod

N. setae 4 4 4 5 4 4 4 4 endopod

N. spines 4 2 5 3 3 3 0 2–5 endopod

Furca

N. spines 10 8 8–11 7 9–10 7 7–8 10–14 Anal operculum Pr (M) NPr NPr NPr NPr NPr Pr (S) Pr (S) Max. / Min. size 2.37 / 2.02 1.78 / 1.1 1.77 / – 1.52 / – 1.9 / 1.83 1.5 / 1.45 2.46 / 2.05 2.7 / 1.5 Habitat R C R R R W R W

8-11-I

1–4

9–11 Pr (M) 2.3 / 1.3 W

Notes: 1. N. remota, Schminke, 1973 (NSW, Australia); 2. N. tasmaniana, Morimoto, 1978 (Tasmania) ; 3. N. williamsi, Schminke, 1973 (Victoria, Australia); 4. N. chiltoni, Schminke, 1973 ( New Zealand); 5. N. hineoneae, Schminke, 1973 ( New Zealand); 6. N. longipes, Schminke, 1978 ( New Zealand); 7. N. lemurum, Drewes and Schminke, 2007 ( Madagascar) ; 8. N octocamura , sp. nov. (Queensland, Australia); and 9. N. pentatrichion , sp. nov. (Queensland, Australia).

A = absent; C = cave; H = homonomous; I = inhomonomous; Max. / Min. = maximum / minimum size in mm; M = medium-sized; Md. = mandible; Mx.I = maxillule; Mx.II = maxilla; N. = number of; NPr = not pronounced; P = present; Pr = pronounced; R = river bank; S = small; sgt = segments; Symp = sympod; Th = thoracopod; Th.I = thoracopod one; W = well.

Notobathynella octocamura sp. nov. is the first species of the genus with five setae on the terminal segment of the antenna, 26–28 teeth on the labrum, 31 setae on the maxilla, two setae on the basipod of thoracopods III to V, three segments in the exopod of thoracopod I, five segments in the exopod of thoracopods IV and V, three setae and two claws in the fourth segment of endopod of the thoracopods II and III, and six setae on the exopod of the uropod. The setal formula of some thoracopods is also unique (see Table 3). All of these characters leave no doubt that the specimens described here represent a new species.

Notobathynella octocamura sp. nov. is the biggest species of the genus (2.7 mm) and contains many teeth, spines and setae on its extremities, and a high number of segments on the thoracopodal exopods. The genus Notobathynella is similar to Billibathynella Cho, 2005 in many aspects. In the new species we find two new characters for the genus that bring it nearer to Billibathynella : two setae on the basipod of the thoracopod III to V ( Notobathynella usually have only one) and three setae and two claws in the four segment of the endopod of the thoracopods II and III, Billibathynella has five or six setae ( Notobathynella usually have only one or two setae and two claws) (see Table 3). In addition, all the species known in the genus have a maximum of four segments in the exopod of the thoracopods (see Table 2), whereas the new species has five, compared with Billibathynella with up to 10 segments.

Notobathynella remota Schminke, 1973 comes from the locality nearest to our new species. Notobathynella remota has six segments on A.II and the new species has five, as is common in the genus (see Table 2). The species with the most characters in common with N. octocamura sp. nov. are N. williamsi Schminke, 1973 (from Victoria), N. hineoneae Schminke, 1973 (from New Zealand), N. remota Schminke, 1973 (from New South Wales) and N. pentatrichion sp. nov., which we describe below.

Unfortunately, previous descriptions of the genus Notobathynella View in CoL have not included detailed drawings of thoracopod VIII of the male of all species (i.e. N. remota ) because a comparison with these would have allowed a more complete understanding of how the new species is related to previous species.