Research Article |
Academic editor: Ingo S. Wehrtmann
© 2019 Xiao-Zhuang Zheng, Wen-Jian Chen, Zhao-Liang Guo.
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Citation:
Zheng X-Z, Chen W-J, Guo Z-L (2019) The genus Macrobrachium (Crustacea, Caridea, Palaemonidae) with the description of a new species from the Zaomu Mountain Forest Park, Guangdong Province, China. ZooKeys 866: 65-83. https://doi.org/10.3897/zookeys.866.32708
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Evidence-based information is the foundation for addressing urgent global challenges in conservation and sustainable management of the freshwater biodiversity. The present study expands current knowledge of the genus Macrobrachium in Zaomu Mountain Forest Park, Guangdong Province based on the morphology, colouration, distribution, and molecular characteristics of Macrobrachium maculatum, M. inflatum, M. nipponense, and an undescribed new species, M. laevis. Macrobrachium laevis sp. nov. can be distinguished from its congeners by a combination of characters, which includes the shape of rostrum, smooth carapace, and male second pereiopod. Macrobrachium laevis sp. nov. displays striking colour pattern, which could help to distinguish this species from other congeneric species in living specimen. Furthermore, the molecular characteristics of mitochondrial cytochrome c oxidase subunit I (COI) showed that this species has a sufficient interspecific divergence from its congeners.
biodiversity, freshwater prawn, molecular phylogeny, morphology, oriental region, taxonomy
The genus Macrobrachium Spence Bate, 1868 comprises 242 species and subspecies inhabiting fresh to brackish environments (
Interest in Macrobrachium as a food has emerged throughout the world because of their delicious and unique flavor, and large size. Macrobrachium species have become an attractive food source, with good economic potential and high commercial interest in China. In addition, some colourful members of the genus Macrobrachium have attracted attention as ornamental pet prawn, and are traded in the ornamental fish market.
The Zaomu Mountain Forest Park (22°43'–22°45'N, 112°45'–112°47'E) was rated as national 4A scenic area in 2012 (
The Zaomu Mountain Forest Park (112°45'–112°47'E, 22°43'–22°45'N) is located in the Youngmei Town, Gaoming District, 38 km West Foshan, Guangdong Province. The area stretches approximately 11 km from north to south and is 5 km wide. The total area is 55 square km. The main mountain peak is 804.5 meters above sea level, and is known as the highest peak of Foshan City (
Samples were collected by a hand net with a mesh size of 0.8 mm. All specimens obtained were fixed in 95 % ethanol. Ethanol was replaced after 24 h with fresh 75 % ethanol. The drawings were made with the aid of a drawing tube mounted on an Olympus BX-41 compound microscope.
Genomic DNA was isolated from the muscle tissue of the abdomen by using the Universal Genomic DNA Kit (Beijing, China). A fragment of the COI (619bp) gene was amplified with conventional polymerase chain reaction (PCR) using two primers LCO1490 (5’-GGTCAACAAATCATAAAGATATTGG-3’) and HCO2198 (5’-TAAACTTCAGGGTGACCAAAAAATCA-3’) (
PCR cycling conditions consisted of a 3 min denaturation at 94 °C, followed by 35 cycles of denaturation at 94 °C for 30 s, annealing at 45–47 °C for 60 s, extension at 72 °C for 60 s, and a final extension at 72 °C for 5 min. PCR amplification sequences were obtained by sanger dideoxy sequencing (Applied Biosystems 3730), after verification with the complementary strand. The sequenced fragments were edited and aligned using Codon Code Aligner v. 8.0.2 (Codon Code Corporation, Dedham, MA, USA) and corrected by the naked eye. All sequences of this study have been deposited in GenBank Nucleotide Sequence Database (see Table
List of locality, geographical coordinates, and GenBank accession numbers of eight palaemonid species used in the present study.
Species | Locality | Geographical coordinates | GenBank |
---|---|---|---|
accession numbers | |||
M. dongaoensis | Dong’ao Island, Zhuhai | 22°01'39"N, 113°42'54"E | MK412789 |
M. formosense | Chancheng, Foshan | 22°56'39"N, 112°53'41"E | MK412773 |
Chancheng, Foshan | 22°56'39"N, 112°53'41"E | MK412780 | |
M. inflatum | Dongfang, Hainan | 18°52'50"N, 108°59'29"E | MK412787 |
Dongfang, Hainan | 18°52'50"N, 108°59'29"E | MK412788 | |
M. laevis sp. nov. | Gaoming, Foshan | 22°43'60"N, 112°47'10"E | MK412774 |
Gaoming, Foshan | 22°43'60"N, 112°47'10"E | MK412775 | |
Heshan, Jiangmen | 22°41'06"N, 112°44'59"E | MK412776 | |
Heshan, Jiangmen | 22°41'06"N, 112°44'59"E | MK412777 | |
Gaoming, Foshan | 22°43'60"N, 112°47'10"E | MK412781 | |
Gaoming, Foshan | 22°43'60"N, 112°47'10"E | MK412782 | |
M. maculatum | Gaoming, Foshan | 22°45'18"N, 112°46'04"E | MK412770 |
Gaoming, Foshan | 22°45'18"N, 112°46'04"E | MK412771 | |
Gaoming, Foshan | 22°45'18"N, 112°46'04"E | MK412785 | |
Gaoming, Foshan | 22°45'18"N, 112°46'04"E | MK412786 | |
M. meridionalis | Chancheng, Foshan | 22°56'39"N, 112°53'41"E | MK412778 |
Chancheng, Foshan | 22°56'39"N, 112°53'41"E | MK412779 | |
M. nipponense | Gaoming, Foshan | 22°39'54"N, 112°41'45"E | MK412772 |
Gaoming, Foshan | 22°45'18"N, 112°46'04"E | MK412783 | |
Gaoming, Foshan | 22°44'49"N, 112°47'04"E | MK412784 | |
Outgroup | |||
P. modestus | Wulanhaote, Neimenggu | 46°19'20"N, 121°54'45"E | MK412768 |
Wulanhaote, Neimenggu | 46°19'20"N, 121°54'45"E | MK412769 |
Six specimens of Macrobrachium laevis sp. nov. and 21 specimens of nine described species, namely Macrobrachium maculatum, M. formosense, M. meridionalis, M. nipponense, M. inflatum, M. dongaoensis, M. asperulum, M. fukienense, and Palaemon modestus were analysed in the prensent study. Sequences of M. asperulum and M. fukienense were obtained from GenBank for comparative and phylogenetic analyses. Two phylogenetic methods, maximum likelihood (ML) and neighbor-joining (NJ) were implemented. The best-fitting model for sequence evolution was determined by Modelgenerator (
The following abbreviations are used throughout the text:
alt altitude,
b breadth,
c carpus,
cl carapace length, measured from the postorbital margin to the posterior margin of the carapace,
f finger,
i ischium,
l length,
m merus,
p palm,
rl rostral length, measured from the rostral tip to the postorbital margin,
stn sampling station,
tl total length, measured from the rostral tip to the posterior margin of the telson.
All measurements are in millimetres. Specimens were deposited in the Department of Animal Science, School of Life Science and Engineering, Foshan University (FU).
Holotype: Adult male (FU, 2018-01-15-01), tl 66.2 mm, cl 18.8 mm, rl 9.4 mm; a stream near the bamboo park, the Zaomu Mountain Forest Park, Guangdong Province China (22°43'60"N, 112°47'10"E, alt. 182 m, stn. 7), 15 January 2018. Paratypes: 7 males (FU, 2018-01-15-02) tl 45.0–61.1 mm, cl 11.8–16.4 mm, rl 7.2–9.3 mm. 14 females, 2 ovigerous females (FU, 2018-01-15-03), tl 39.8–61.5 mm, cl 9.9–17.3 mm, rl 6.5–9.3 mm, same data as for holotype. Paratypes: 2 males (FU, 2018-01-15-04), tl 32.1–48.8 mm, cl 8.0–14.2 mm, rl 5.0–8.0 mm. 1 female, tl 40.0 mm, cl 11.0 mm, rl 5.9 mm, a small stream near the Luohan hill, Heshan, Jiangmen City, Guangdong Province China (22°41'10"N, 112°43'33"E, alt. 140 m, stn.11), 12 May 2018. Paratypes: 8 males (FU, 2018-01-15-05), tl 43.3–51.2 mm, cl 11.8–14.4 mm, rl 8.5–10.1 mm. 14 female, 10 ovigerous females, tl 39.2–60.1mm, cl 10.1–16.5 mm, rl 6.5–9.6 mm, Longquan Gorge near Heshan, Jiangmen City, Guangdong Province China (22°41'6"N, 112°44'59"E, alt. 180 m, stn. 10), 12 May 2018.
Rostrum 0.51–0.71 of cl, tip slightly bent downwards, reaching to end of third segment of antennular peduncle. Rostral formula: 3-4+5-8/2-3 (usually 3), teeth equally spaced. Cephalothorax, abdomen, and second pereiopods smooth, without microspinules. Second pereiopods shorter than tl in both sexes; merus 1.0–1.2 times as long as the ischium; carpus 4.5–5.2 times as long as width, 1.2–1.4 times as long as merus and 0.8–1.0 times as long as palm. Palm not inflated, 4.8–5.3 times as long as wide. Movable finger 0.66–0.86 times as long as palm, without any gape when crossed. Fixed finger with one proximal tooth; moveable finger with two proximal teeth. All segments smooth, with only a small amount of spines along the lateral surfaces of the palm. Eggs large; size 1.1–1.4 × 1.5–1.8 mm diameter.
Rostrum (Fig.
Carapace (Fig.
Antennule (Fig.
Antenna (Fig.
Mandibles, maxillulae, maxillae, first maxillipeds, second maxillipeds and branchial formula typical for genus. Third maxillipeds with robust endopod and ischiomerus slightly bow-shaped, with rows of long simple setae on distal inner and outer margins. Carpus 0.70 times length of ischiomerus, with row of long simple setae on inner margin and sparse row of simple setae on outer margin; distal segment 0.83 times of penultimate segment, with long simple setae on inner margin. Exopod reaching distal end of ischiomerus, with plumose setae distally, basal with well-developed oval lateral plate; two arthrobranchs, one rudimentary, obscured by the larger one.
First pereiopods (Fig.
Second pereiopods (Fig.
Third pereiopods (Fig.
Fourth pereiopods (Fig.
Fifth pereiopods (Fig.
First pleopods of male with endopod of approximately half-length of exopod, slightly concave at inner margin, tip rounded, without appendix interna.
Second pleopods with well-developed appendix masculina, reaching middle of endopod, approximately twice as long as appendix interna with numerous stiff setae.
Abdomen (Fig.
Telson (Fig.
Uropodal diaeresis with a spine shorter than lateral angle.
Eggs large, size 1.1–1.4 × 1.5–1.8 mm.
The juvenile was yellowish and semi-transparent (Fig.
Neighbour-joining (NJ) and maximum likelihood (ML) trees inferred from partial COI sequences (619 bp) from ten species of Palaemonidae, including the new species, are shown in Figure
Phylogenetic relationships among Macrobrachium laevis sp. nov. and the other nine species, analysed by maximum likelihood (ML) and neighbour-joining (NJ) methods with Palaemon modestus as the out-group taxa. Bootstrap values of ML (left) and NJ (right) are indicated above the branches of the clades.
Pairwise genetic distance among nine Marobrachium prawn species based on the COI gene.
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | |
(1) M. maculatum | 0.138 | 0.169 | 0.166 | 0.167 | 0.167 | 0.192 | 0.171 | 0.103 | |
(2) M. asperulum | 0.138 | 0.162 | 0.160 | 0.171 | 0.171 | 0.203 | 0.151 | 0.135 | |
(3) M. inflatum | 0.169 | 0.162 | 0.014 | 0.053 | 0.053 | 0.197 | 0.146 | 0.148 | |
(4) M. nipponense | 0.166 | 0.160 | 0.014 | 0.050 | 0.050 | 0.193 | 0.144 | 0.145 | |
(5) M. formosense | 0.167 | 0.171 | 0.053 | 0.050 | 0.001 | 0.208 | 0.147 | 0.137 | |
(6) M. meridionalis | 0.167 | 0.171 | 0.053 | 0.050 | 0.001 | 0.208 | 0.146 | 0.138 | |
(7) M. dongaoensis | 0.192 | 0.203 | 0.197 | 0.193 | 0.208 | 0.208 | 0.207 | 0.182 | |
(8) M. fukienense | 0.171 | 0.151 | 0.146 | 0.144 | 0.147 | 0.146 | 0.207 | 0.155 | |
(9) M. laevis sp. nov. | 0.103 | 0.135 | 0.148 | 0.145 | 0.137 | 0.139 | 0.192 | 0.155 |
Species name is derived from laevis (Latin) in reference to the smoothness of the segments of the second pereiopod, carapace, and abdomen.
Macrobrachium laevis sp. nov. shows close similarity with M. maculatum
Morphological characteristics of Macrobrachium laevis sp. nov. and the congeners.
M. laevis sp. nov. | M. maculatum | M. asperulum | M. fukienense | M. inflatum | M. nipponense | M. dongaoensis | |
---|---|---|---|---|---|---|---|
Rostrum | |||||||
Number of dorsal teeth | 8–12 | 9–14 | 8–12 | 7–9 | 12–17 | 9–13 | 10–13 |
Number of postal orbit teeth | 3–4 | 3–5 | 2–3 | 1–2 | 3–4 | 2–3 | 4–5 |
Number of ventral teeth | 2–3 | 3–5 | 2–3 | 1–2 | 3–5 | 2–3 | 1–3 |
Ratio of RL/CL | 0.5–0.7 | 0.6–0.7 | 0.6–0.7 | 0.6 | 1.0 | 0.6–0.8 | 0.5–0.7 |
First pereiopod Ratio of f/p | 0.73–0.97 | 0.76–0.83 | 0.78 | 0.85 | 0.83–0.91 | 0.8 | 1.0 |
Second pereiopod | |||||||
Ratio of palm L/b | 4.8–5.3 | 4.5–6.0 | 5.0–6.5 | 4.3 | 3.5–3.6 | 4.7–7.0 | 4.3–4.9 |
Ratio of f/p | 0.66–0.86 | 0.62–0.78 | 0.5–0.6 | 0.4–0.5 | 0.82–1.0 | 0.6–0.7 | 0.69–0.78 |
Ratio of c/p | 0.8–1.0 | 0.8–0.9 | 0.79–0.84 | 0.76–0.87 | 1.4 | 1.4 | 0.93–1.0 |
Ratio of c/m | 1.2–1.4 | 1.1–1.3 | 1.3–1.4 | 1.1 | 1.4–1.5 | 1.6–1.7 | 1.1–1.4 |
Ratio of i/m | 0.83–1.0 | 0.76–1.0 | 0.78 | 0.6–0.7 | 1.1 | 0.74–0.9 | 0.9 |
Ratio of f/m | ≥1 | <<1 | <<1 | <<1 | =1 | <1 | >1 |
Microspinules on every segment | Smooth, except magrins of palm with scatted microspinules | All segments with | All segments with | All segments with | All segments without, except pout margin of palm with | All segments with | All segments with |
Distribution of the second tooth of moveable finger | On the proximal 1/4 | On the proximal 1/5 | On the proximal 2/5 | On the proximal 1/2 | On the proximal 1/7 | On the proximal 1/5 | On the proximal 1/5 |
Eggs size (mm) | 1.1–1.4 × 1.5–1.8 | 1.6–1.7 × 2.1–2.4 | 1.08–1.26 × 1.50–1.76 | 1.5–1.6 × 2.1–2.2 | 0.53–0.59 × 0.62–0.69 | 0.54–0.68 × 0.72–0.86 | 0.33–0.42 × 0.37–0.44 |
Scaphocerite l/b | 2.4–2.6 | 3.5 | 2.8–3.2 | 2.5–2.8 | 3.4 | 2.7–3.1 | 3.4 |
Specimens of Macrobrachium laevis sp. nov. were collected from two streams and a river. The stream was near bamboo park, the Zaomu Mountain Forest Park, Foshan City (22°43'60"N, 112°47'10"E, alt. 182 m, stn. 7) (Fig.
So far only known from the type locality and nearby localities in the Guangdong Province, southern China.
Five females, tl 48.5–52.8 mm, cl 14.2–16.3 mm, 4 males, tl 51.3–65.9 mm, cl 18.0–25.6mm, Sibao Reservoir, Heshan, Jiangmen City (22°44'14"N, 112°50'17"E, alt. 84 m, stn. 1), 3 September 2017; 2 females, tl 48.5–50.4 mm, cl 15.2–16.4 mm, 1 male, tl 51.3 mm, cl 17.3mm, Lingshan Garden, Gaoming, Foshan City (22°45'42"N, 112°44'39"E, alt. 44.9 m, stn. 2), 17 May 2018; 3 females, tl 46.3–49.2 mm, cl 14.1–15.3 mm, 2 males, tl 51.3–61.4 mm, cl 18.2–23.4 mm, Xikong Reservoir, Gaoming, Foshan City (22°42'35"N, 112°43'25"E, alt. 22.4 m, stn. 3), 17 May 2018; 2 females, tl 42.5–44.1 mm, cl 13.2–14.6 mm, 4 males, tl 48.3–59.4 mm, cl 17.4–22.9 mm, Yangmei River, Gaoming, Foshan City (22°45'18"N, 112°46'04"E, alt. 49 m, stn. 5), 9 September 2017; 4 females, tl 41.4–50.3 mm, cl 12.3–16.3 mm, 3 males, tl 47.2–65.5 mm, cl 17.5–24.5 mm, stream near Hengkong Village, Gaoming, Foshan City (22°44'49"N, 112°47'04"E, alt. 72 m, stn. 6), 9 September 2017; 1 female, tl 42.5 mm, cl 13.2, 1 male, tl 48.3 mm, cl 16.7 mm, a stream near Datian Village, Gaoming, Foshan City (22°44'22"N, 112°46'36"E, alt. 56 m stn. 9), 17 May 2018.
Macrobrachium nipponense were found in reservoirs, streams, rivers, and ponds of the Zaomu Mountain Forest Park. The species is native and broadly distributed throughout East Asia (i.e. China, Japan, Korea, Vietnam, and Myanmar), (
China, Japan, Korea, Myanmar, and Vietnam.
Three females, tl 45.8–54.0 mm, cl 12.0–18.3 mm, 4 males, tl 35.6–75.8 mm, cl 9.6–19.8 mm, Yangmei River, Gaoming, Foshan City (22°45'18"N, 112°46'04"E, alt. 49 m, stn. 5), 9 September 2017.
The present specimens are consistent with the original description and illustration by
The body is very dark brown, the cephalothorax has diagonal yellow stripes, and the abdomen has large spots (Fig.
Southeastern China (Anhui, Hunan, Fujian, and Guangdong Provinces).
Two females, tl 46.8–50.2 mm, cl 13.8–15.3 mm, 1 male, tl 52.1 mm, cl 14.2 mm, Qianlonggu, Gaoming, Foshan City (22°42'48"N, 112°44'54"E, alt. 124 m, stn. 4), 9 September 2017; 2 females, tl 45.5–51.0 mm, cl 13.4–16.1 mm, 3 males, tl 46.5–60.1 mm, cl 15.2–21.3 mm, Yangmei River, Gaoming, Foshan City (22°45'18"N, 112°46'04"E, alt. 49 m, stn. 5), 9 September 2017; 3 females, tl 40.5–54.3 mm, cl 12.5–20.6 mm, 2 males, tl 41.5–65.2 mm, cl 16.2–23.7 mm, Sibao Reservoir, Heshan, Jaingmen City (22°44'14"N, 112°50'17"E, alt. 84 m, stn.1), 17 August 2017.
Specimens were confidently assigned to the present species due to their inflated palm, the upturned rostrum and the rostral formula, as well as the ratio of the segments in the male second pereiopods. Macrobrachium inflatum is usually found together with M. nipponense.
The body is translucent and light green. The rostrum is transparent to almost colourless. The cephalothorax has blue-black diagonal strips, and the abdomen shows blue-black transverse strips. The second pereiopods have transversal yellow bands on the merus and carpus. All joints of third to fifth pereiopods have transversal yellow bands. The eggs are yellow (Fig.
Southeastern China (Jiangsu, Anhui, Hunan, Guangdong, and Yunnan Provinces).
This study was supported by the project “Survey of marine and coastal biodiversity protection in prioritised region of national environmental protection project” (PM-zx097-201812-244). Part of this work was funded by Guangdong Provincial Key Laboratory of Animal Molecular Design and Precise Breeding, School of Life Science and Engineering, Foshan University, Foshan, 528231, Guangdong, China (2018A02), and by a special fund for the cultivation of science and technology innovation of the university students in Guangdong in 2019 (climbing plan) (pdjh2019b0510). Additional support for this project was provided by Guangdong College students’ innovation and entrepreneurship (XJ2018247 and XJ2018222). Special thanks to Dr. EI-Ashram Saeed and Werner Klotz for correcting the manuscript. We are grateful to Célio Magalhães and another anonymous reviewer who provided very useful suggestions, which improved of our work. We also thank Xiaoxue Bao, Chunjun Zhong, Guocai Guo, Dengxu Li, and Zilong Huang, students of the Foshan University, for helping us to collect the studied specimens used for this study.