Research Article |
Corresponding author: Azman bin Abdul Rahim ( abarahim@gmail.com ) Academic editor: Michael Ohl
© 2018 Melvin Chew, Azman bin Abdul Rahim, Nurul Yuziana binti Mohd Yusof.
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:
Chew M, Abdul Rahim A, Mohd Yusof NY (2018) A new species of Eisothistos (Isopoda, Cymothoida) and first molecular data on six species of Anthuroidea from the Peninsular Malaysia. Zoosystematics and Evolution 94(1): 73-81. https://doi.org/10.3897/zse.94.23000
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A new species of expanathurid (Eisothistos tiomanensis sp. n.) is described and illustrated. It was collected from Pulau Tioman, Malaysia and can be distinguished by the unique bipartite shape of its uropodal exopod. Accalathura borradailei, Apanthura pariensis, A. stocki, Expanathura corallis and Mesanthura quadrata in the Malaysian waters are recorded for the first time. Additionally, six sequences of cytochrome c oxidase subunit I (COI) genes are presented. These are the first molecular evidence of anthuroids from the waters of Malaysia.
Isopoda, Anthuroidea, Expanathuridae, Leptanthuridae, Anthuridae, Eisothistos tiomanensis, Accalathura borradailei, Apanthura pariensis, Apanthura stocki, Expanathura corallis, Mesanthura quadrata, Pendanthura tinggiensis, Tinggianthura alba, COI
The Anthuroidea Leach, 1814 are a distinctive group of mainly marine isopods (
DNA barcoding was first suggested just over two decades ago (
Anthuroids have been primarily studied using morphological methods, in particular, dissection of specimens and cladistic analysis. It is only in the recent years that molecular documentations have slowly emerged such as the work of
The specimens in this study were obtained from coral reef areas around Peninsular Malaysia. Coral rubble was collected into a 56 litres bucket with sea water via SCUBA diving and were moderately broken up. About 10 drops of 37 % formaldehyde were added and left to stand for about 30 minutes. Next, the samples were rinsed and washed with seawater passing through a 500 µm sieve. In the field, samples were fixed with about 10 % formalin in seawater. Molecular specimens were obtained in the same manner except that they were laced with about 1 litre of absolute ethanol and left to stand for about 15 minutes. They were placed directly into precooled absolute ethanol (0 ºC) and kept in an icebox which was carried throughout the field sampling to maximize tissue preservation.
At the laboratory, the specimens were sorted and conserved separately in 4 % formalin in water in vials. Specimens were then identified and new species was selected for dissection. Whole bodies and dissected appendages were mounted in glycerol and illustrated under a Leica DMLB light microscope equipped with a camera lucida. Materials are deposited in the Muzium Zoologi, Universiti Kebangsaan Malaysia, Malaysia. The following abbreviations are used: A, antenna; AM, appendix masculina; MD, mandible; MP, maxilliped; MX, maxilla; P, pereopod; PL, pleopod; PLT, pleotelson U, uropod; UN, uropod endopod; UX, uropod exopod; UKMMZ, Universiti Kebangsaan Malaysia Muzium Zoologi.
Before extraction, residual ethanol was removed from the tissue by evaporation at room temperature. The samples were left opened covered only with a Kimwipes tissue until they were completely desiccated. DNA was extracted from whole organism using DNeasy Blood and Tissue Kit (Qiagen, USA).
The COI sequences were amplified using the
Purified PCR products were cloned using E. coli Top 10 (Invitrogen) and Thermo Scientific CloneJET PCR Cloning Kit (Thermo Fisher Scientific, USA). Colonies containing the vector along with the cloned PCR fragments were picked with a sterile pipette tip and put in to 20 µl of water. This was mixed and 1 µl was taken as the DNA template for PCR colony screening. Successful clones were purified using the innuPREP Plasmid Rapid Kit (Analytik Jena AG, Germany) and sequences were generated on an automated DNA Sequencer ABI 3100 (Applied Biosystems Inc., USA) using the ABI PRISM Dye Terminator Cycle Sequencing Ready Reaction v3.0 kit (Applied Biosystem Inc., USA).
Raw COI sequences were assigned to Phred quality score of 30 in order to assess the quality (
Apanthura pariensis Negoescu, 1997: 186-194, figs 6–10.
43 females, 2 males, UKMMZ-1585, Pangkor Laut, Pulau Pangkor, Perak, Malaysia, 4°11'22.32"N; 100°32'50.22"E (DMS), C. Melvin, 15 April 2014, coral rubble, ~3 m; 9 females, UKMMZ-1586, Pantai Kok, Pulau Langkawi, Kedah, Malaysia, 6°21'56.05"N; 99°40'31.13"E (DMS), C. Melvin, 4 November 2013, intertidal; 8 females, 2 males, UKMMZ-1587, Pantai Kok, Pulau Langkawi, Kedah, Malaysia, 6°21'56.05"N; 99°40'31.13"E (DMS), C. Melvin, 8 March 2015, intertidal.
Pari Island, Java Sea, Indonesia (type locality); Pulau Pangkor, Malaysia; Pulau Langkawi, Malaysia.
A 726 base pairs of COI sequence (GenBank: MF680510) was acquired from one individual of A. pariensis. No insertion or deletion in the sequence alignment.
Amakusanthura stocki Müller, 1991: 595–600, figs. 30–56.
Apanthura stocki Müller, 1992a: 166.
1 female, 1 male, UKMMZ-1576, Mentinggi, Pulau Tinggi, Johor, Malaysia, 2°16'21.67"N; 104°7'18.61"E (DMS), C. Melvin, 19 April 2013, coral rubble, ~3 m; 3 females, 1 male, UKMMZ-1577, Kampung Pasir Panjang, Pulau Tinggi, Johor, Malaysia, 2°17'37.96"N; 104°6'1.97"E (DMS) E, C. Melvin, 18 December 2012, coral rubble, ~3 m; 14 females, UKMMZ-1578, Sebirah Kechil, Pulau Tinggi, Johor, Malaysia, 2°18.622'N; 104°05.616'E (DDM), C. Melvin, 18 April 2013, coral rubble, ~3 m; 13 females, 1 male, UKMMZ-1579, Pulau Seri Buat, Pahang, Malaysia, 2°41'13.59"N; 103°55'25.99"E (DMS), C. Melvin, 19 April 2014, coral rubble, ~7 m; 4 females, UKMMZ-1580, Kampung Pasir Panjang, Pulau Tinggi, Johor, Malaysia, 2°17'37.96"N; 104°6'1.97"E (DMS), C. Melvin, 15 June 2015, coral rubble, ~3 m; 27 females, UKMMZ-1581, Batu Bonchek, Pulau Dayang, Johor, Malaysia, 2°28'40.90"N; 104°30'19.12"E (DMS), C. Melvin, 26 July 2016, coral rubble, ~3 m; 6 females, UKMMZ-1582, Teluk Rha, Pulau Aur, Johor, Malaysia, 2°28'17.24"D; 104°30'53.14"E (DMS), C. Melvin, 27 July 2016, coral rubble, ~3 m.
Sri Lanka (type locality); Pulau Besar, Malaysia; Pulau Tinggi, Malaysia; Pulau Seri Buat, Malaysia.
A 712 base pairs of COI sequence (GenBank: MF680509) was acquired from one individual of A. stocki. No insertion or deletion in the sequence alignment.
The Malaysian A. stocki differs slightly from the original material by its weakly serrated inner margin of uropodal endopod and acute distal margin of uropodal exopod in female.
Mesanthura quadrata Kensley & Schotte, 2000: 2080-2083, figs. 17–18.
3 immature females, UKMMZ-1595, Pulau Seri Buat, Pahang, Malaysia, 2°41'13.59"N; 103°55'25.99"E (DMS), C. Melvin, 19 April 2014, coral rubble, ~7 m; 1 immature female, UKMMZ-1596, Batu Malang, Pulau Tioman, Pahang, Malaysia, 2°54'15.44"N; 104°6'1.08"E (DMS), C. Melvin, 18 April 2014, coral rubble, ~7 m; 1 female, UKMMZ-1597, Kampung Pasir Panjang, Pulau Tinggi, Johor, Malaysia, 2°17'37.96"N; 104°6'1.97"E (DMS), C. Melvin, 15 June 2015, coral rubble, ~3 m; 1 female, UKMMZ-1598, Sebirah Kechil, Pulau Tinggi, Johor, Malaysia, 2°18.622'N; 104°05.616'E (DDM), C. Melvin, 15 June 2015, coral rubble, ~3 m; 29 juveniles, UKMMZ-1599, Kampung Pasir Panjang, Pulau Tinggi, Johor, Malaysia, 2°17'37.96"N; 104°6'1.97"E (DMS), C. Melvin, 13 October 2012, artificial substrate unit, ~3 m; 1 female, UKMMZ-1560, Sebirah Kechil, Pulau Tinggi, Johor, Malaysia, 2°18.622'N; 104°05.616'E (DDM), C. Melvin, 18 April 2013, coral rubble, ~3 m.
Mahé Island, Seychelles (type locality); Pulau Seri Buat, Malaysia; Pulau Tioman, Malaysia; Pulau Tinggi, Malaysia.
n/a.
Mesanthura quadrata is recorded for the first time from the Southeast Asia region.
Pendanthura tinggiensis Chew et al., 2016: 232-238, figs 2–8.
Pulau Tinggi, Malaysia.
A 709 base pairs of COI sequence (GenBank: MF680512) was acquired from one individual of P. tinggiensis. No insertion or deletion in the sequence alignment.
The material used in this study is taken from the study of
Tinggianthura alba Chew et al., 2014: 1-11, figs 3–9.
Pulau Tinggi, Malaysia.
A 658 base pairs of COI sequence (GenBank: MF680513) was acquired from one individual of T. alba. No insertion or deletion in the sequence alignment.
The material used in this study is taken from the study of
Adult male, UKMMZ-1559, Labas, Pulau Tioman, Pahang, Malaysia, 2°53'13.71"N; 104°3'54.65"E (DMS), C. Melvin, 18 April 2014, coral rubble, ~15 m.
Holotype, adult male.
Total body length 2.2 mm (tip of rostrum to base of telson), approximately 9.9 times as long as greatest width. Cephalon with minute rostrum; eyes grossly enlarged, containing many ommatidia laterally. Pereonites 1–7 progressively shorter, pereonites 2–3 longest, each 1.3 times as long as pereonite 1, pereonites 4–5 each the same length as pereonite 1, pereonite 6 about 0.7 times length of pereonite 5, pereonite 7 half as long as pereonite 5, pereonites 4–6 anteriorly narrow, subdistally widest, pereonite 7 anteriorly narrow, widest posteriorly. Pleonites 1–5 progressively shorter with pleonites 1–2 of similar length, pleonite 3 about 0.8 times as long as pleonite 2, pleonites 4 about 0.7 times as long as pleonite 3, pleonite 5 shortest half as long as pleonite 4, posterior margin of pleonite 6 with a medial cleft.
Antenna 1 peduncle article 1 subquadrate, articles 2–3 progressively shorter; flagellum of 9 articles with short proximal article bearing numerous aesthetascs, articles 2–9 progressively narrower, articles 2–6 each bearing 2 aesthetascs and 1 seta, articles 7–8 each bearing 1 aesthetasc distally, terminal article with 3 apical setae.
Antenna 2 peduncle articles equal, articles 1–2 each bearing 2 setae, article 3 with 1 seta, article 4 elongate, 2.4 times as long as wide, article 5 longest, twice as long as article 4; flagellum of 6 articles, progressively smaller, articles 1–4 each with 1 distal aesthetasc, article 5 with 2 distal setae, terminal article with 4 apical setae.
Mouthparts reduced.
Pereopod 1 basis 3.3 times as long as greatest width, anterior margin with 1 medial seta, posterior margin with 1 subdistal seta and fine setae; ischium 3.2 times as long as greatest width, posterior margin subdistally with 1 seta and fine setae; merus anterior margin convex distally, bearing 2 setae, posterior margin with fine setae; carpus anterior margin half the length of posterior margin, posterior margin with 1 seta, with 4 submarginal spinules; propodus 4.4 times as long as greatest width, palm weakly concave with 21 submarginal spinules, anterior margin with 1 distal seta, palmar margin with 1 posterodistal robust seta; unguis half as long as propodus.
Pereopod 2 basis 3.7 times as long as greatest width, posterior margin with 1 subdistal seta and fine setae; ischium 3.1 times as long as greatest width, anterior margin with 2 setae, posterior margin with 2 setae and fine setae; merus anterior margin convex, bearing 1 seta, posterior margin with fine setae; carpus anterior margin half the length of posterior margin, posterior margin with 1 seta and fine setae; propodus 3.9 times as long as greatest width, anterior margin with 2 setae, palmar margin with 1 medial robust seta and 1 posterodistal robust seta, fine setae and subdistal palmar comb; unguis half the length of propodus.
Pereopod 3 basis 3.3 times as long as greatest width, anterior margin with 2 setae and fine setae, posterior margin with 1 seta and fine setae; ischium 3.2 times as long as greatest width, anterior margin with 2 setae and fine setae, posterior margin with 1 seta and fine setae; merus anterior distal margin convex bearing 2 setae, posterior margin with 1 seta, carpus anterior margin one third length of posterior margin, posterior margin with 1 seta; propodus 3.6 times as long as greatest width, anterior margin with 2 setae, palmar margin with fine setae, 2 setae, subdistal palmar comb, 1 medial robust seta and 1 posterodistal robust seta; unguis half as long as propodus.
Pereopod 4 basis 3.9 times as long as greatest width, anterior margin with 2 setae and fine setae, posterior margin with 1 seta and fine setae; ischium 3 times as long as greatest width, anterior margin with 1 seta, posterior margin with 2 setae; merus anterior margin convex, bearing 1 seta, posterior margin with 1 seta, carpus linear twice as long as wide anterior margin with 2 setae, posterior margin with setae comb, 1 seta and 1 robust seta; propodus 4.5 times as long as greatest width, anterior margin with 3 setae, palmar margin bordered with setae comb, 1 medial robust seta and 1 posterodistal robust seta; unguis 0.8 times as long as propodus.
Pereopod 5 basis 4.1 times as long as greatest width, anterior margin with 1 seta, posterior margin with 1 seta and fine setae; ischium 4.1 times as long as greatest width, anterior margin with 1 seta, posterior margin with 3 setae and fine setae; merus anterior margin subdistally convex, bearing 2 setae, posterior margin with fine setae; carpus linear 2.4 times as long as greatest width, anterior margin with 1 seta, posterior margin with setae comb, 1 distal seta and 1 distal robust seta; propodus 4.6 times as long as greatest width, anterior margin with 1 distal seta, palmar margin bordered with setae comb, 1 medial robust seta and 1 posterodistal robust seta; unguis 0.8 times the length of propodus.
Pereopod 6 basis 4 times as long as greatest width, anterior margin with 3 setae and fine setae, posterior margin with 1 subdistal seta; ischium 3.8 times as long as greatest width, anterior margin with fine setae, posterior margin with 3 setae and fine setae; merus anterior margin convex, bearing 1 seta, posterior margin with 1 seta; carpus linear 2.6 times as long as greatest width, anterior margin with 1 seta, posterior margin bordered with setae comb, distally with 1 seta and 1 robust seta; propodus 5.3 times as long as greatest width, palmar margin bordered with setae comb, proximally with 1 robust seta, medially with 1 robust seta and posterodistally with 1 robust seta; unguis 0.7 times the length of propodus.
Pereopod 7 basis 4.1 times as long as greatest width, anterior margin with 1 seta, posterior margin with 1 seta; ischium 3.2 times as long as greatest width, anterior margin with 1 seta and fine setae, posterior margin with 3 setae and fine setae; merus slender 3.6 times as long as greatest width with anterior margin slightly convex, bearing 1 seta, posterior margin with 1 seta; carpus linear 3.2 times as long as greatest width, anterior margin with 1 seta, posterior margin with setae comb and 1 robust seta; propodus 7.5 times as long as greatest width, anterior margin with 3 setae, palmar margin bordered with setae comb, 1 medial robust seta and 1 posterodistal robust seta; unguis half as long as propodus.
Pleopod 1 with elongated rami, sympod rectangular; exopod slender 4.3 times as long as greatest width, apex truncated bearing 6 plumose setae; endopod shorter than exopod 0.75 times the length of exopod, apex truncated bearing 5 plumose setae.
Pleopod 2 sympod subrectangular; exopod 3 times as long as wide, apex truncated bearing 7 plumose setae; endopod slender 4.8 times as long as greatest width, apex truncated bearing 5 plumose setae; appendix masculina almost as long as endopod, ending in a somewhat hook-like with a rounded end.
Pleopod 3 not available.
Pleopod 4 sympod subrectangular, inner margin with 1 seta; exopod broadened 1.8 times as long as greatest width, apex truncated bearing 8 plumose setae, medial lateral margin with 1 seta; endopod as long as exopod 1.3 times as long as exopod with apical margin truncated bearing 6 plumose setae.
Pleopod 5 shorter than others with sympod subquadrate; exopod much smaller than endopod half as long as endopod bearing 3 plumose setae; endopod broadend 1.8 times as long as greatest width bearing 2 plumose setae, apical margin medially with two small protuberances.
Uropod sympod with serrated inner margin, inner distal margin raised with an acute apex, outer distal margin raised with 2 acute serrations apically; endopod elongate with serrated margin bearing 13 setae, apically with 1 short robust plumose sensory spine; exopod bipartite with 5 setae proximally, medially with a central elongated spike having 3 subdistal setae and apical margin concave bearing 1 short plumose sensory spike, outer margin with a short slender spike bearing 1 seta apically, inner margin obsolete.
Pleotelson 2.2 times as long as greatest width, narrowest anteriorly, widest near posterior end, dorsal surface with 4 pairs of setae and a middorsal row of 7 obscure denticles, subdistal margin with 2 obscure teeth on each side, posterior margin strongly dentate with 10 teeth and 5 pairs of setae.
This species is named after the type locality, Pulau Tioman, Malaysia.
n/a.
Only one male specimen is available. The male Eisothistos in general, differs from the female by its grossly enlarged eyes, antenna 1 with short basal article bearing numerous aesthetascs, reduced mouthparts, pleonites 1–3 elongate and pleopods 1–3 with elongated peduncles and rami (
The uropodal exopod form in the Eisothistos can be divided into two types. While most possess the tripartite uropodal exopod shape, several others are described with the uncommon bipartite uropodal exopod shape. Eisothistos tiomanensis sp. n. belongs to the latter group with Eisothistos anomala, E. corinellae, E. macquariensis and E. minutus (
Eisothistos sp. n. is readily distinguishable from the other Malaysian species, E. besar Müller, 1992 by its bipartite uropodal exopod (tripartite in E. besar) and the surface of pleotelson with 7 obsure middorsal teeth (4 distinct middorsal teeth in E. besar).
Panathura collaris
Kensley, 1979a: 823-827, figs 7–9;
54 females, 3 males, UKMMZ-1567, Sebirah Kechil, Pulau Tinggi, Johor, Malaysia, 2°18.622'N, 104°5.616'E (DDM), C. Melvin, 16 May 2013, coral rubble, ~3 m; 12 females, UKMMZ-1568, Mentinggi, Pulau Tinggi, Johor, Malaysia, 2°16'21.67"N; 104°7'18.61"E (DMS), C. Melvin, 19 April 2013, coral rubble, ~3 m; 56 females, 9 males, UKMMZ-1569, Batu Malang, Pulau Tioman, Pahang, Malaysia, 2°54'15.44"N; 104°6'1.08"E (DMS), C. Melvin, 18 April 2014, coral rubble, ~7 m; 35 females, 2 males, UKMMZ-1570, Labas, Pulau Tioman, Pahang, Malaysia, 2°53'13.71"N; 104°3'54.65"E (DMS), C. Melvin, 18 April 2014, coral rubble, ~15 m; 14 females, 4 males, PLAy2-iso4d, Pantai Kok, Pulau Langkawi, Kedah, Malaysia, 6°21'56.05"N; 99°40'31.13"E (DMS), C. Melvin, 8 March 2015, coral rubble, intertidal; 7 females, 1 male, PDYx1-iso4e, Batu Bonchek, Pulau Dayang, Johor, Malaysia, 2°28'40.90"N; 104°30'19.12"E (DMS), C. Melvin, 26 July 2016, coral rubble, ~3m.
Fiji (type locality); Cook Island; Chesterfield and Melish Reefs, Moorea, Coral Sea; Lord Howe I, Tasman Sea; Papua New Guinea; Northern Territory, Queensland, Australia; Pulau Dayang, Pulau Tinggi, Malaysia; Pulau Tioman, Malaysia; Pulau Langkawi, Malaysia.
A 631 base pairs of COI sequence (GenBank: MF680512) was acquired from one individual of E. collaris. No insertion or deletion in the sequence alignment.
Expanathura collaris is a widespread species dwelling in coral reef rubble especially within the Southeastern Pacific and Australian region (Kensley 1979a;
Calathura borradailei
Stebbing, 1904: 700, pl. 49A;
Accalathura borradailei
Barnard, 1925: 149;
35 females, 3 males, UKMMZ-1612, Kampung Pasir Panjang, Pulau Tinggi, Johor, Malaysia, 2°17'37.96"N; 104°6'1.97"E (DMS), C. Melvin, 28 February 2013, coral rubble, intertidal; 34 females, UKMMZ-1613, Kampung Pasir Panjang, Pulau Tinggi, Johor, Malaysia, 2°17'37.96"N; 104°6'1.97"E (DMS), C. Melvin, 18 December 2012, coral rubble, intertidal; 1 female, UKMMZ-1614, Kampung Pasir Panjang, Pulau Tinggi, Johor, Malaysia, 2°17'37.96"N; 104°6'1.97"E (DMS), C. Melvin, 15 June 2015, coral rubble, intertidal; 20 females, UKMMZ-1615, Sebirah Kechil, Pulau Tinggi, Johor, Malaysia, 2°18.622'N; 104°05.616'E (DDM), C. Melvin, 15 June 2015, coral rubble, intertidal; 14 females, 1 male, UKMMZ-1616, Batu Bonchek, Pulau Dayang, Johor, Malaysia, 2°28'40.90"N; 104°30'19.12"E (DMS), C. Melvin, 26 July 2016, coral rubble, ~3 m.
Maldives, Fadifolu (type localtiy); Thailand; Chilka Lake, India; Quilon, India; Pulau Tinggi, Malaysia.
A 684 base pairs of COI sequence (GenBank: MF680508) was acquired from one individual of E. collaris. No insertion or deletion in the sequence alignment.
This is the first record of Accalathura borradailei from the waters of Malaysia.
The authors would like to thank Universiti Kebangsaan Malaysia, Sultan Iskandar Marine Park–Johor National Parks, and the Department of Marine Park Malaysia. This research was supported by the Universiti Kebangsaan Malaysia under Grant No. LIV-2015-02.