Research Article |
Corresponding author: Stefan Eberhard ( stefan@subterraneanecology.com.au ) Academic editor: Oana Teodora Moldovan
© 2016 Danny Tang, Stefan Eberhard.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Tang D, Eberhard SM (2016) Two new species of Nitocrella (Crustacea, Copepoda, Harpacticoida) from groundwaters of northwestern Australia expand the geographic range of the genus in a global hotspot of subterranean biodiversity. Subterranean Biology 20: 51-76. https://doi.org/10.3897/subtbiol.20.10389
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In Australia, the Ameiridae is the most diverse harpacticoid family in groundwater, with 35 species hitherto reported. In this study, we describe two new species belonging to the “vasconica”-group of the ameirid genus Nitocrella based on specimens collected from groundwaters near mine sites in the Pilbara and Great Sandy Desert regions of northwestern Australia. Nitocrella knotti sp. n. can be distinguished from related taxa by having two setae on the antennal exopod, four armature elements on the distal endopodal segment of leg 2, four armature elements on the distal endopodal segment of leg 3, three armature elements on the distal endopodal segment of leg 4, and three setae on the basoendopodal lobe of leg 5. Nitocrella karanovici sp. n. differs from its congeners by having a short outer spine and long inner seta on the distal endopodal segment of leg 2, three armature elements on the distal endopodal segment of leg 3, and four setae on the basoendopodal lobe of leg 5 in the female. This study is of biogeographic interest in providing the first documentation of the genus Nitocrella from the Pilbara and Great Sandy Desert regions. Both new species of Nitocrella are recorded from restricted localities and appear to be short-range endemics, thus making them potentially vulnerable to environmental changes and threatening processes such as mining. The distribution range of N. karanovici sp. n. coincides with the centre of diversity of the Ethel Gorge aquifer stygobiont community, a globally significant hotspot which is listed as endangered.
Short-range endemic, stygofauna, compliance monitoring, mining
The family Ameiridae (Copepoda) has successfully colonized and radiated in continental surface water and groundwater, with over 150 species reported from Australia, Asia, Europe, and North America (
Harpacticoid copepods of the family Ameiridae reported from subterranean waters of Australia (in alphabetical order).
Species | State* | Reference |
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Abnitocrella eberhardi Karanovic, 2006 | WA |
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Abnitocrella halsei Karanovic, 2006 | WA |
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Antistygonitocrella pardalotos Karanovic, Eberhard, Perina & Callan, 2013 | WA |
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Archinitocrella newmanensis Karanovic, 2006 | WA |
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Biameiropsis barrowensis Karanovic, 2006 | WA |
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Gordanitocrella trajani Karanovic & Hancock, 2009 | WA |
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Haifameira pori Karanovic, 2004 | WA |
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Hirtaleptomesochra bispinosa Karanovic, 2004 | WA |
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Inermipes humphreysi Lee & Huys, 2002 | WA |
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Kimberleynitocrella billhumphreysi Karanovic & Hancock, 2009 | WA |
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Lucionitocrella yalleenensis Karanovic & Hancock, 2009 | WA |
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Megastygonitocrella bispinosa (Karanovic, 2006) | WA |
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Megastygonitocrella dec Karanovic & Hancock, 2009 | WA |
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Megastygonitocrella ecowisei Karanovic & Hancock, 2009 | WA |
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Megastygonitocrella embe Karanovic, Eberhard, Perina & Callan, 2013 | WA |
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Megastygonitocrella kryptos Karanovic & Hancock, 2009 | QLD |
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Megastygonitocrella pagusregalis Karanovic & Hancock, 2009 | QLD |
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Megastygonitocrella trispinosa (Karanovic, 2006) | WA |
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Megastygonitocrella unispinosa (Karanovic, 2006) | WA |
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Nitocrella absentia Karanovic, 2004 | WA |
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Nitocrella obesa Karanovic, 2004 | WA |
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Nitocrella trajani Karanovic, 2004 | WA |
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Nitocrellopsis halsei Karanovic, 2010 | WA |
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Nitocrellopsis operculata Karanovic, 2010 | WA |
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Nitocrellopsis pinderi Karanovic, 2010 | WA |
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Nitokra esbe Karanovic, Eberhard, Cooper & Guzik, 2014 | WA |
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Nitokra humphreysi Karanovic & Pesce, 2002 | WA |
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Nitokra lacustris (Schmankevitsch, 1895) | SA |
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Nitokra lacustris pacifica Yeatman, 1983 | WA |
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Nitokra yeelirrie Karanovic, Eberhard, Cooper & Guzik, 2014 | WA |
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Novanitocrella aboriginesi Karanovic, 2004 | WA |
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Paranitocrella bastiani Tang & Knott, 2009 | WA |
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Parapseudoleptomesochra karamani Karanovic, 2004 | WA |
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Parapseudoleptomesochra rouchi Karanovic, 2004 | WA |
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Parapseudoleptomesochra tureei Karanovic, 2006 | WA |
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Groundwaters of (semi-) arid Western Australia are a globally significant hotspot for subterranean biodiversity (
The majority of ameirid species known from groundwater in Australia were collected at, or adjacent to, proposed mine sites which have been surveyed for stygofauna as part of the mine project environmental impact assessment, or, as part of the ongoing environmental compliance monitoring at established mine sites. Other ameirids were collected from pastoral wells and groundwater boreholes during the course of surveys by government departments, museums, and universities. Most of the described ameirids are recorded from single localities and appear to be short-range endemic species (sensu
The net-haul method (see
Copepod specimens selected for taxonomic study were soaked in lactophenol prior to examination using a Leica M205C dissecting microscope and Leica MD2500 compound microscope equipped with differential interference contrast. Selected specimens were measured using an ocular micrometer, dissected, and examined using the wooden slide procedure of
Borehole HB54/4.1 (= Borehole HB405) (21°28'45"S; 121°46'45"E) on Telfer Road, 48 km NW of Telfer mine site and 350 km SE of Port Hedland, Western Australia, July 2008, J. Mifsud leg.
Holotype female (
Female. Body (Fig.
Nitocrella knotti sp. n., adult female: A habitus, dorsal B urosomites 2–5 and caudal rami, ventral C anal somite and caudal rami, dorsal D rostrum, dorsal E right antennule with segments 3, 5 and 6 shown separately and aesthetasc indicated by arrowhead, ventral F left antenna with one apical element shown separately, anterior. Scale bars: A 200 µm; B 100 µm; C, E, F 25 µm; D 2 µm.
Caudal ramus (Fig.
Rostrum (Fig.
Antennule (Fig.
Antenna (Fig.
Labrum (Fig.
Mandible (Fig.
Maxillule (Fig.
Maxilla (Fig.
Maxilliped (Fig.
Legs 1–4 biramous (Figs
Coxa | Basis | Exopod | Endopod | |
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Leg 1 | 0-0 | I-I | I-0; I-I; II,2,0 | 0-I; 0-0; 0,3,0 |
Leg 2 | 0-0 | I-0 | I-0; I-I; II,2,0 | 0-I; 0,I+1,II |
Leg 3 | 0-0 | 1-0 | I-0; I-I; II,2,0 | 0-I; 0,I+1,1+I |
Leg 4 | 0-0 | 1-0 | I-0; I-I; II,2,2 | 0-I; 0,I+1,I |
Leg 1 (Fig.
Leg 2 (Fig.
Leg 3 (Fig.
Leg 4 (Fig.
Leg 5 (Fig.
Leg 6 (Fig.
Male. Unknown.
One paratype with 5 elements on terminal exopodal segment of left leg 1 (Fig.
This species is named in honour of the late Professor Brenton Knott (The University of Western Australia) who made significant contributions to research on groundwater fauna in Western Australia.
Among the three groups of Nitocrella proposed by
Species of Nitocrella belonging to the “vasconica”-group (in alphabetical order).
Species | Locality | Reference |
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N. absentia Karanovic, 2004 | Australia |
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N. afghanica Štĕrba, 1973 | Afghanistan |
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N. beatricis Cottarelli & Bruno, 1993 | Sardinia (Italy); Corsica (France) |
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N. caraioni Petkovski, 1976 | Cuba |
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N. dussarti Chappuis & Rouch, 1959 | Pyrenees (France) |
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N. gracilis Chappuis, 1955 | Pyrenees (France) |
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N. knotti sp. n. | Australia | Present study |
N. jankowskajae Borutzky, 1972 | Kirgiziya (= Kyrgyzstan) |
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N. karanovici sp. n. | Australia | Present study |
N. kirgizica Borutzky, 1972 | Kirgiziya (= Kyrgyzstan) |
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N. mara Löffler, 1959 | Iran |
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N. monchenkoi Borutzky, 1972 | Uzbekistan |
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N. motasi Petkovski, 1976 | Cuba |
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N. nana Štĕrba, 1973 | Afghanistan |
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N. obesa Karanovic, 2004 | Australia |
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N. paceae Pesce, 1980 | Iran |
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N. stetinai Štĕrba, 1973 | Afghanistan |
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N. trajani Karanovic, 2004 | Australia |
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N. unispinosa Shen & Tai, 1973 | China |
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N. vasconica Chappuis, 1937 | Spain |
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N. yokotai Miura, 1962 | Japan |
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Borehole UNK02 (23°15'00"S; 119°53'41"E), Ethel Gorge aquifer, approximately 15 km ENE of Newman (Fig.
Holotype female (
All material collected from boreholes in the Ethel Gorge aquifer, approximately 15 km ENE of Newman, Western Australia (Fig.
Female. Body (Fig.
Nitocrella karanovici sp. n., adult female: A habitus, dorsal B urosomites 2–5 and caudal rami, ventral C genital double-somite, lateral D anal somite and caudal rami, dorsal E anal somite and left caudal ramus, lateral F rostrum, dorsal. Scale bars: A 100 µm; B 50 µm C, D, E 25 µm; F 5 µm.
Caudal ramus (Fig.
Rostrum (Fig.
Antennule (Fig.
Nitocrella karanovici sp. n., adult female: A right antennule with segments 3, 5, 6 and 7 shown separately and aesthetasc indicated by arrowhead, ventral B right antenna, anterior C labrum, posterior D left mandible, posterior E left maxillule, anterior F left maxilla, anterior G right maxilliped, posterior. Scale bars: A 50 µm; B, C 20 µm; D, E, F, G 10 µm.
Antenna (Fig.
Labrum (Fig.
Mandible (Fig.
Maxillule (Fig.
Maxilla (Fig.
Maxilliped (Fig.
Legs 1–4 biramous (Fig.
Coxa | Basis | Exopod | Endopod | |
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Leg 1 | 0-0 | I-I | I-0; I-I; III,2,0 | 0-I; 0-0; 0,I+2,0 |
Leg 2 | 0-0 | I-0 | I-0; I-I; II,2,1 | 0-I; 0,I+1,0 |
Leg 3 | 0-0 | 1-0 | I-0; I-I; II,2,1 | 0-I; 0,I+1,I |
Leg 4 | 0-0 | 1-0 | I-0; I-I; II,2,1+I | 0-I; 0,I+1,0 |
Leg 1 (Fig.
Leg 2 (Fig.
Leg 3 (Fig.
Leg 4 (Fig.
Leg 5 (Fig.
Leg 6 (Fig.
Male. Body length (measured from tip of rostrum to posterior margin of caudal rami) 400–440 µm (mean 417 µm; n = 7); body width 90–95 µm (mean 91 µm; n = 7). Prosome composed of cephalothorax and 3 free pedigerous somites. Urosome comprised of fifth pedigerous somite, genital somite and 4 free postgenital somites. Genital somite (Fig.
Nitocrella karanovici sp. n., adult male (A, B, C, D) and adult female (E, F, G, H, I, J): A urosomites 2–6 and caudal rami, ventral B left antennule with segments 3, 4, 6 and 7 shown separately and aesthetasc indicated by arrowhead, ventral C right leg 1 basis, anterior D right leg 5, ventral E terminal exopodal segment of right leg 1, anterior F terminal exopodal segment of left leg 3, anterior G terminal endopodal segment of left leg 3, anterior H same, anterior I basis and endopod of right leg 4, anterior J endopod of left leg 4, anterior. Scale bars: A 50 µm; B, I 25 µm; C, D, G, H, J 10 µm; E, F 20 µm.
Antennule (Fig.
Inner spine on basis of leg 1 (Fig.
Leg 5 (Fig.
Leg 6 (Fig.
One paratype female with discontinuous row of spinules along posteroventral margin of anal somite (Fig.
This species is named for Dr. Tomislav Karanovic, in recognition of his extensive taxonomic research on subterranean copepods of Australia.
Nitocrella karanovici sp. n. also belongs to the “vasconica”-group as it possesses the distinctive six armature elements on the distal exopodal segment of leg 4. Of the other 20 species in this group, N. karanovici sp. n. shares five armature elements on the distal exopodal segment of leg 1 with only N. dussarti Chappuis & Rouch, 1959 and N. gracilis Chappuis, 1955. Nitocrella karanovici sp. n. can be easily distinguished from N. dussarti by having three armature elements (instead of four) on the distal endopodal segment of leg 3 and four setae (instead of three) on both the exopod and basoendopodal lobe of leg 5 in the female, and from N. gracilis by having a short outer spine and long inner seta (rather than two subequal setae) on the distal endopodal segment of leg 2, two spines and one seta (instead of one spine and two setae) on the distal endopodal segment of leg 3, and four setae (instead of 3) on the basoendopodal lobe of leg 5 in the female.
This study is of biogeographic interest in providing the first documentation of the genus Nitocrella from the Pilbara and Great Sandy Desert regions of northwestern Australia. Previously in Australia, Nitocrella was known only from three species in the northern Yilgarn region (
Comparison of morphological characters between female Nitocrella species reported from Western Australia.
Character | N. absentia | N. obesa | N. trajani | N. knotti sp. n. | N. karanovici sp. n. |
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Genital and first abdominal somites fused ventrally | No | No | No | Yes | Yes |
Integumental window on body | Absent | Absent | Absent | 1 present on 2nd and 3rd prosomites and on 3rd urosomite | 1 pair present on 2nd and 3rd urosomites |
Spinules along posterior margin of anal operculum | Present | Absent | Present | Present | Present |
No. of setae on antennal exopod | 3 | 3 | 3 | 2 | 3 |
No. of armature elements on distal exopodal segment of leg 1 | 4 | 4 | 4 | 4 | 5 |
Spinules on distolateral lobes of intercoxal sclerite of leg 2 | Absent | Present | Absent | Present | Absent |
No. of armature elements on distal exopodal segment of legs 2 and 3 | 5 | 4 | 4 | 4 | 5 |
No. of armature elements on distal endopodal segment of leg 2 | 4 | 3 | 3 | 4 | 2 |
No. of armature elements on distal endopodal segment of leg 3 | 4 | 3 | 4 | 4 | 3 |
Outer spine on middle exopodal segment of leg 4 | Absent | Present | Present | Present | Present |
No. of armature elements on distal endopodal segment of leg 4 | 4 | 3 | 3 | 3 | 2 |
No. of armature elements on basoendopodal lobe of leg 5 | 4 | 1 | 4 | 3 | 4 |
The collection records for both Nitocrella karanovici sp. n. and N. knotti sp. n. strongly suggest that each species is a short-range endemic (SRE), with their recorded distribution ranges being much less than the SRE thresholds of 10 000 km2 nominated by
Out of more than 40 boreholes monitored over numerous surveys at Ethel Gorge, N. karanovici sp. n. has only been recorded from eight boreholes that span a linear range of less than 14 km (Figure
Eighty-four species of stygofauna have been recorded from the Ethel Gorge aquifer and adjacent groundwaters in the Newman area, thus ranking it as one of the richest localized groundwater fauna assemblages in Australia, and indeed globally (
The Ethel Gorge aquifer stygobiont community is listed in Western Australia as an endangered Threatened Ecological Community (TEC) by the Department of Parks and Wildlife (
The field surveys at Ethel Gorge were funded by BHP Billiton Iron Ore, and the surveys at Telfer by Newcrest Mining. Professor Pierre Horwitz kindly provided the specimens from Telfer, which were collected by Joe Mifsud. Giulia Perina, Peter Bell, Natasha Coen, and Steven Catomore (Subterranean Ecology Pty Ltd) collected the copepod samples at Ethel Gorge; Giulia also assisted with drafting the maps. The taxonomic descriptions were funded by Subterranean Ecology Pty Ltd. Helpful comments received from two reveiwers were appreciated and improved the manuscript.