Muccanella cundalinensis Perina and Camacho, 2019

Perina, Giulia, Camacho, Ana I., Huey, Joel, Horwitz, Pierre & Koenders, Annette, 2019, The role of allopatric speciation and ancient origins of Bathynellidae (Crustacea) in the Pilbara (Western Australia): two new genera from the De Grey River catchment, Contributions to Zoology 88 (4), pp. 452-497 : 484-489

Muccanella cundalinensis Perina and Camacho sp. nov. ( figs. 10–12 )

Zoobank: urn:lsid:zoobank.org:act:42CAEBC3-AE62-4346-9C20-E0E0AE64DCFC

Type locality. Bore CU 0046, Cundaline Ridge, De Grey River Catchment, Pilbara, Western Australia (see appendix 3 for borehole coordinates) .

Material examined

Holotype. WAMC57340 , male, permanent slide, bore CU0046, 29 May 2009, Bell & Barnet.

Allotype. WAMC57337 , female, permanent slide, bore CU0046, 29 May 2009, Bell & Barnet.

Paratypes. WAMC57338 , female, whole specimen for DNA, bore CU0046, 29 May 2009, Bell & Barnet ; WAMC57339 , female, whole specimen for DNA, bore CU0046, 29 May 2009, Bell & Barnet ; WAMC57341 , female, permanent slide, bore CU0046, 29 May 2009, Bell & Barnet ; WAMC57343 , male, permanent slide, bore CU0064, 21 July 2009, Bell ; WAMC57344 , female, whole specimen for DNA, bore CU0064, 21 July 2009, Bell ; WAMC57347 , female, permanent slide, bore CU0064, 21 July 2009, Bell ; WAMC57348 , male, whole specimen for DNA, bore CU0064, 21 July 2009, Bell ; WAMC57363 , female, permanent slide, bore CU0058, 29 May 2009, Bell & Barnet ; WAMC57364 , male, permanent slide, bore CU0058, 29 May 2009, Bell & Barnet ; WAMC57365 , female, whole specimen for DNA, bore CU0058, 29 May 2009, Bell & Barnet ; WAMC57366 , juvenile, whole specimen for DNA, bore CU0058, 29 May 2009, Bell & Barnet ; WAMC57368 , female, permanent slide, bore CU0285, 30 May 2009, Bell & Barnet ; WAMC59198 , male, permanent slide, bore CU0058, 10 June 2009, Bell & Ridley ; WAMC59199 , sex not recorded, permanent slide, bore CU0058, 10 June 2009, Bell & Ridley ; WAMC59205 , female, permanent slide, bore CU0058, 29 May 2009, Bell & Barnet ; WAMC59206 , male, permanent slide, bore CU0064, 21 July 2009, Bell ; WAMC59207 , male, permanent slide, bore CU0064, 21 July 2009, Bell ; WAMC59208 , male, permanent slide, bore CU0064, 21 July 2009, Bell ; WAMC59209 , male, permanent slide, bore CU0046, 29 May 2009, Bell & Barnet ; WAMC59210 , female, permanent slide, bore CU0046, 29 May 2009, Bell & Barnet ; WAMC59211 , male, permanent slide, bore CU0046, 29 May 2009, Bell & Barnet ; WAMC59212 , male, permanent slide, bore CU0046, 29 May 2009, Bell & Barnet ; WAMC59213 , female, permanent slide, bore CU0046, 29 May 2009, Bell & Barnet ; WAMC59214 , male, permanent slide, bore CU0046, 29 May 2009, Bell & Barnet ; WAMC59215 , male, permanent slide, bore CU0046, 29 May 2009, Bell & Barnet ;

Abbreviations used: Th, thoracopod; A.I, antennule; A.II, antenna; Md, mandible, Mx.I, maxillule and Mx.II maxilla.

Description (based on adults)

Body. Total length of holotype about 0.95 mm and allotype 0.94 mm. Total length of males 0.82–1.08 mm, of females 0.92–1.07 mm. Body almost cylindrical, nearly six times as long as wide; segments slightly widening towards posterior end. Head as long as wide. Pleotelson with one plumose dorsal seta on either side. All drawings are of the holotype and allotype except for fig. 10C, E.

Antennule (fig. 10A). Seven-segmented; length of first three segments as long as the last three; first and last segments are the longest, then sixth, second and third of similar length and fourth slightly shorter, fifth very small; inner flagellum small and longer than wide; setation as in fig. 10A; two aesthetascs on both sixth and seventh segments.

Antenna (fig. 10B). Seven-segmented; nearly as long as A.I; first four segments almost as long as the last three combined; fifth (third of endopod) very small, without setae; terminal segment is the longest, fourth and sixth segments similar in length and about three-fourth the length of seventh segment; setal formula: 0/1+exp/2+0/1+0/0/2+0/5; exopod 0.8 times the length of the first segment, with two terminal setae, one smooth and one bifurcated sensory seta; ventromedial seta absent.

Labrum (fig.10D,E).Almostsquare,withsmoothfree edge, and with two small lobes on the distal part.

Paragnath (fig. 10C). Almost rectangular, strong long claw on distal part with thick setation.

Mandible (fig. 10F, G). Palp with three segments, terminal segment with two long and strong barbed claws of similar length, more or less cylindrical without expansions. Masticatory part: pars incisiva with two teeth; processus incisivus accessorius with one tooth and one seta-like tooth; pars molaris with three teeth close to processus incisivus accessorius and one distal strong tooth with one denticle on each side.

Maxillule (fig. 10H). Proximal endite with four setae; distal endite with six teeth, four with denticles and two setae-like, and three plumose setae in outer margin of endite.

Maxilla (fig. 10I). Four-segmented; setal formula 7, 3, 7, 5.

Thoracopods I-VII (fig. 11A–G). Epipod present on Th I to VII. Th I coxa with a long and strong plumose seta and an external bundle of thin hair; basipod with two smooth setae. One-segmented exopod, shorter than endopod on all thoracopods; exopod reaches about the middle of the third segment of endopod in all thoracopods; it bears four barbed setae on Th I, two terminal, one dorsal and one ventral; and five barbed setae on Th II to VII. Exopod of thoracopos I to VI with tuft of setules on ventral margin (on dorsal margin too on thoracopod I). Endopod with four segments in all thoracopods, setal formulae (number of setae on basipod in brackets):

Th I: (2) 3+0/2+1/2+0/3

Th II: (1) 2+0/2+1/2+0/3

Th III: (1) 2+0/1-2+1/1+0/3

Th IV-V: (1) 2+0/2+1/1+0/3

Th VI- VII: (1) 1+0/0+1/0+0/2(1)

Male thoracopod VIII ( fig. 12A–D ). Compact and trapezoidal, with one small lobe (outer lobe) on penial region (latero external part). Small frontal and posterior projection (Fr. pr; P. pr.) integrated in penial region. Basipod vertical with small crest on distal end; endopod small, rectangular, with one short seta; exopod with simplified morphology, curved outward, almost perpendicular to the main axis of basipod and bearing two setae of slightly unequal length on distal part. Penial region well developed.

First pleopod ( fig. 12F ). Two segmented, first segment enlarged with one long seta; second segment with eight smooth setae, two distal of similar length and shorter than all the others.

Female allotype thoracopod VIII ( fig. 12E ). Coxa without setae; basipod rectangular bearing one inner seta; one ramus two-segmented, same size of basipod, with two setae of different length (one thick and very long) on distal end; very large epipod, about twice the length of basipod.

Female allotype Th I-VII. Number of segments of endopods and exopods as in male holotype. Number of setae on segments of endopod and basipod differs from male holotype. Setal formulae of allotype (number of setae of basipod in brackets at the start):

Th I: (2) 3+0/2+1/2+0/3

Th II: (1) 2+0/2+1/2+0/3

Th III: (1) 2+0/2+1/1+0/3

Th IV-V: (1) 2+0/2+1/1+0/3

Th VI- VII: (1) 1+0/0+1/0+0/2(1)

Uropods ( fig. 12H ). Sympod 1.5 times the length of endopod, rectangular, about 1.5 times longer than wide, with four spines of similar length. Endopod with spinous projection on distal outer corner, 2.5 times longer than exopod, with two strong claws (“uropodial claws” sensu Delamare Deboutteville & Serban, 1973) (distal one 2.5 times longer than proximal one); one “special seta” (“X”, which correspond to the first claw on Bathynella according toDelamare Deboutteville & Serban, 1973); one plumose seta near the base on the ventral edge; one long terminal and one short subterminal seta, longer than distal claw and ventrally located. Exopod with four setae: two medial setae and two terminal (one very long and thick, and one short and thinner).

Pleotelson ( fig. 12G ). With one long, plumose dorsal seta on either side near the base of furca.

Furcal rami ( fig. 12G ). Small, almost square, bearing five spines; first spine is the longest, about three times the length of the second one; second and third spines of similar length and 2/3 shorter than dorsal one; fourth spine shortest.

Variability

The number of setae on segments of endopod of thoracopods and second segment of pleopod can vary (usually one more or one less seta).

Etymology

The genus name comes from the name of the station near the type locality: Muccan Station ). The species name derives from the Cundaline ridge where the species was collected .

Figures

FIGURE 10 Muccanella cundalinensis gen.et sp.nov., male holotype (A, B, D, F, H, I); female allotype (E, G); male paratype (C). (A) Antennula (dorsal view); (B) antenna (dorsal view); (C) Paragnath male WAMC57343; (D) labrum; (E) labrum female WAMC57341; (F) palp and mandible male holotype; (G) palp and mandible female allotype; (H) maxillule; (I) maxilla.Scale bar in mm.

FIGURE 11 Muccanella cundalinensis gen.etsp.nov.,male holotype.(A) ThoracopodI; (B) thoracopodII;(C) thoracopod III; (D) thoracopodIV;(E)thoracopod V;(F)Thoracopod VI;(G)thoracopod VII.Scale bar inmm.

FIGURE 12 Muccanella cundalinensis gen.et sp.nov., (A–D, F–H) male holotype; female allotype (E).(A, B) thoracopod VIII (posterior view); (C, D) thoracopod VIII (frontal view); (E) thoracopod VIII female allotype (frontal view); (F) first pleopod; (G) furcal ramus and dorsal seta (dorsal view); (H) uropod (dorsal view). Scale bar in mm. Abbreviations:O.lb, outer lobe; Bsp, basipod; Endp,. endopod Exp, exopod P.pr, posterior projection; Fr.pr, frontal projection.