Eulimnadia pinocchionis, Brian V Timms, 2016

Brian V Timms, 2016, A partial revision of the Australian Eulimnadia Packard, 1874 (Branchiopoda: Spinicaudata: Limnadiidae), Zootaxa 4066 (4), pp. 351-389 : 376-379

Eulimnadia pinocchionis sp. nov.

( Figs 9 F, 15)

Etymology. The specific name refers to the fictional character in Carlo Colloidi’s novel ‘ The Adventures of Pinocchio.’ The unusually long rostrum of this species reminds me of the extraordinary long nose of Pinocchio who I admired as a boy.

Type locality. Western Australia, 25 km SW of Karratha, gnamma on granite on Karratha Station, 20o 54’ 32.23”S, 116o 42’ 9.54”E, 12 May 2005, A Pinder & J. Macrae.

Type material. Holotype. Male 4.1 mm long, 2.7 mm high, registration number WAM C 59035 in Western Australian Museum, Perth.

Allotype. Female 4.6 mm long, 2.9 mm high, registration number WAM C 59036 in Western Australian Museum, Perth.

Paratypes. Male 4.0mm long, 2.7 mm high and female 4.9 mm long and 3.2 mm high, registration number AM P 97819 in Australian Museum, Sydney.

Other Material. 7 males, 9 females, Western Australia, 25 km SW of Karratha, gnamma on granite on Karratha Station, 20o 54’ 32.23”S, 116o 42’ 9.54”E, 12 May 2005, A Pinder & J. Macrae, WAM C59037.

Diagnosis. Eggs spherical with almost 100 elongated shallow polygons with rudentiform edges (i.e. edges uneven like rope). Male with a narrow triangular rostrum protruding about 2x the ocular tubercle and clasper with 5–6 spines at palpomere junctions. Telson with a double row of about 12 spines evenly spaced and sized (except for first and last) and sometimes with an extra spine anterior to the rows and cercopod with 10–11 setae of length 1.5– 2 x diameter of cercopod..

Description. Egg ( Fig 9 F) spherical, mean diameter 161 Μm (range 157–185 Μm, n =5) and averaging 97 (range 90–102) shallow polygons. These polygons about twice as long as wide, somewhat irregular in shape and with ropey edges and uneven inner surfaces. Central groove indistinct. No outgrowths where edges of adjacent polygons meet. Surface minutely microporous.

Male. Head ( Fig 15 C) with a prominent ocular tubercle with a round compound eye occupying most (ca 80%) of it. Rostrum triangular, narrow and long, protruding 2x as much as the ocular tubercle. Frons-rostrum angle about 100o. Ocellus about one third the size of the eye and located in the middle of the rostrum. Dorsal organ posterior to the eye by about its height, pedunculate and with a flattened apex and height only about half of the ocular tubercle.

First antenna about twice as long as the peduncle of the second antenna and with about 9 lobes, each with numerous tiny sensory setae.

Second antenna with a spinose peduncle, each flagella with 8 antennomeres, dorsally with 1–3 spines and ventrally with 1–5 long setae. Dorsal spines less numerous in basal and four most distal antennomeres, and most antennomeres with 3–4 ventral setae, the lower numbers on the basal antennomeres.

Carapace ( Fig 15 A) basically rectangular with rounded corners and a few growth lines. Adductor muscle scar hardly visible.

Thoracopods. Eighteen pairs, the first two modified as claspers ( Fig 15 G). Both claspers with palm trapezoidal but with a small rounded projection mediodistally, apical club rounded with thick denticles distomedially and spines apicolaterally, and moveable finger of normal curved structure with suctorial disc apicoventrally. First clasper with palp 1.5 x palm length, second clasper with palp about 2.5x palm length, both with about six short spines, one or two longer than the others, located medially at junction of palpomeres.

Other thorocopods of typical structure for Eulimnadia , decreasing in size and complexity posteriorly. Dorsal surface of trunk with 1–3 short spines posteriorly on each of the posterior 8 trunk segments.

Telson ( Fig 15 E) with about 11 pairs of dorsal spines, the anterior ones well spaced and the first the largest. A subsidiary single spine anterior to the double row. Most spines naked or occasionally with a denticle or two. Caudal filaments originating from a mound a little higher than the dorsal floor of the telson and between the 2nd and 3rd spine. Dorsal floor lowering evenly posterior of the mound to the cercopod base. Cercopods a little longer than the dorsum of the telson, the basal three-quarters hardly thinning to a small spine, then rapidly thinning to an acute apex. About 10 setae, each almost 2x diameter of cercopod, though the first a little shorter. A cirrus of many tiny denticles on each dorsolateral edges of the apical quarter. Prominent spiniform projection beneath the cercopods at the ventroposterior corner of the telson.

Female. Head ( Fig 15 D) with ocular tubercle prominent, with compound eye occupying most (ca 80%) of it. Rostrum subequal in size to the ocular tubercle and assuming a smooth asymmetrical bulge at an angle of about 120o to the frons and with the dorsal part occupied by an ocellus about half the size of the eye. Dorsal organ posterior to the eye as in the male.

First antennae subequal in length to the peduncle of the second antennae with about 4 small lobes each with short sensory hairs.

Second antennae as in male.

Carapace ovate oval and somewhat vaulted anteriodorsally.

Thoracopods. Eighteen of typical Eulimnadia structure.

Trunk dorsum with 3–9 setae terminally, these setae few, short and stout on posterior few segments, numerous and longer on segments 8–15 and hardly any setae on anterior trunk segments 1–7.

Telson ( Fig 15 F) as in male, but with about 12 spines and about 11 cercopod setae. No extra spine anterior to the double row of dorsal telsonic spines.

Comments. This species is distinctive by reason of its long rostrum in the male and the egg with many shallow polygons with ropey edges rather than deep and with minor frilly edges. Also E. pinocchionis sp. nov. has 11–12 evenly spaced and sized telsonic spines and also the 10–11 cercopod setae about 1.5– 2 x the cercopod diameter, and the claspers usually have 6 spines at the junction of the palpomeres instead of the usual 5. The extra telsonic spine seen in the holotype is often absent in other specimens. While this combination of features distinguishes it from other Australian Eulimnadia , it is very different from E. dahli which occurs in the same area, but apparently not in gnammas. Eulimnadia dahli eggs have many fewer polygons (about 30), which are deep and with frilly edges. Furthermore it has numerous (>18) long cercopod setae, more (>15) telsonic spines, as well as a shorter male rostrum and five spines at the palpomere junctions.

Given the almost equal numbers of males and apparent females in the original collection, this species may be unlike the other Eulimnadia species described in this revision and not utilize androdioecious reproduction.

Distribution and ecology. Eulimnadia pinocchionis sp. nov. is known only from its type locality, a gnamma on a granite outcrop in the Pilbara, WA. Gnammas are rare in the Pilbara, so it may well have a limited distribution and population. While this may indicate a precarious conservation position, most gnammas are rarely compromised by human activities.

Figures

FIGURE 9. Eulimnadia eggs. A, E. contraria sp. nov. (Lake Dunn, Qld); B, E. gnammaphila Kooyoora, Vic); C, E. gnammaphila (Peela, SA); D, E. gnammaphila (Yanneymooning, WA); E. hansoni (Bloodwood, NSW); F, E. pinocchionis (Karratha, WA), G, E. taroomaensis (Taroom, Qld), H, E. uluruensis (Uluru, NT); enlargement of portion of egg of E. uluruensis. Scale bars 1 mm, except I for which the bar = 0.01 mm.

FIGURE 15. Eulimnadia pinocchionis sp. nov. Karratha, WA. A, male carapace; B, female carapace; C, male head and antennae; D, female head; E, male telson; F, female telson; G, male clasper. Scale bars 1 mm.