Biodiversity Data Journal :
Taxonomic Paper
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Corresponding author: Do Van Tu (dovantu.iebr@gmail.com)
Academic editor: Tin-Yam Chan
Received: 17 Jun 2021 | Accepted: 07 Sep 2021 | Published: 27 Sep 2021
© 2021 Do Van Tu, Kristina von Rintelen, Werner Klotz, Le Hung Anh, Tran Anh Tuan, Dang Van Dong, Phan Thi Yen, Nguyen Tong Cuong, Hoang Ngoc Khac, Phan Dang, Thomas von Rintelen
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:
Tu DV, von Rintelen K, Klotz W, Hung Anh L, Anh Tuan T, Van Dong D, Thi Yen P, Tong Cuong N, Ngoc Khac H, Dang PD, von Rintelen T (2021) Taxonomy notes and new occurrence data of four species of atyid shrimp (Crustacea: Decapoda: Atyidae) in Vietnam, all described from China. Biodiversity Data Journal 9: e70289. https://doi.org/10.3897/BDJ.9.e70289
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Freshwater shrimp of the family Atyidae De Haan, 1849 have been studied in Vietnam for more than a century. A total of 24 species of atyid shrimps from the genera Caridina H. Milne Edwards, 1837, Neocaridina Kubo, 1938, Atyopsis Chace, 1983 have been recorded from Vietnam. With 22 species, the majority are from the genus Caridina. In 2013, Karge and Klotz mentioned the occurrence of four yet undescribed species belonging to Paracaridina Liang, Guo & Tang, 1999 in Vietnam without taxonomic details.
In general, studies of freshwater atyids in Vietnam are limited and most Vietnamese taxa await a taxonomic revision. The available data do not fully reflect their estimated species diversity in the country and distribution data are deficient. Here, we focus on four species of atyid shrimps from two genera, viz. Caridina cantonensis Yu, 1938, C. lanceifrons Yu, 1936, C. serrata Stimpson, 1860 and Neocaridina palmata (Shen, 1948), all described from China and have been reported to occur in Vietnam. The previous reports on the occurrence of these species in Vietnam are largely unreliable due to taxonomic confusion. To contribute to the knowledge of these taxa, we provide the first verified distribution records of the four species in the country with some taxonomic remarks.
This study shows the first taxonomically-verified distribution data of four atyid shrimp species originally described from China, but also reported from Vietnam, albeit under various species names and, in some cases, erroneously. These data allow the first meaningful discussion of the distribution in light of the reproductive strategy of these four species and, in conjunction with the taxonomic remarks, will contribute to the knowledge of these taxa. As a result of this research and data from previous studies, we now consider all four species as widespread and non-endemic, but land-locked (with a complete freshwater life cycle). In Vietnam, all four species are confined to the northern half of the country. Beyond Vietnam, we provide the first records for Caridina lanceifrons from southern Thailand, which suggests a major sampling gap in Indochina.
freshwater fauna, Caridina, Neocaridina, taxonomy, distribution
Freshwater shrimps of the family Atyidae (
Most recent taxonomic research on atyids – traditional and integrative – has focused on Southeast Asia, but the atyid fauna of Indochina including Vietnam has been largely neglected. Virtually all of the few studies in this region have been conducted in Vietnam and all are purely taxonomic. At present, 24 described atyid species from four genera, including Caridina Milne Edwards, 1837 (
The taxonomic confusion in atyids in general and Vietnamese taxa, in particular, does not only make it difficult to obtain accurate estimates of species diversity, but also prevents the use of existing data for biogeographic or evolutionary studies, as species distribution cannot be reliably assessed.
Four species, Caridina cantonensis Yu, 1938, C. lanceifrons Yu, 1936, C. serrata Stimpson, 1860 and Neocaridina palmata (Shen, 1948), were originally described from China (
We collected atyid specimens in different habitats including rivers, streams, lakes and caves from the mainland to islands throughout Vietnam between 2003 and 2020. The collected sites were partially chosen for their accessibility (Fig.
All collected samples were identified to species level, based on existing descriptions. The specimens were dissected and observed by using a Leica MZ 12 stereomicroscope. Voucher specimens are deposited in the Institute of Ecology and Biological Resources (IEBR), Vietnam Academy of Science and Technology (VAST), Ha Noi, Vietnam, the Museum für Naturkunde (MfN), Berlin, Germany (collection codens: ZMB), Ha Noi University of Science (HUS) and Oxford University Museum of Natural History (OUMNH). In addition to the data of the collected samples in Vietnam, we used records of the four species from China and other areas from the collection of Museum für Naturkunde (MfN), Berlin, Germany and the literature. For the latter, we only used records that could be georeferenced with reasonable accuracy and precision (< ca. 1 km radius across point locality) from authors who are experts on atyids. Based on these criteria, all records from
In the description, all terminology used follows
Caridina cantonensis Yu, 1938: 290, figs. 7–8. [Type locality: Qing’ao Village, Nan’ao County, Guangdong Province, China; neotype designation by
Caridina mutata Cai & Ng, 1999: 1624; figs. 12–13. [Type locality: mountain stream near Fangcheng Town, Fangcheng County, Guangxi Province, China]
Material examined for description. Caridina cantonensis Yu, 1938: 7 males, cl 3.5–4.1, 4 females, cl 4.0–4.8 (ZMB 30253), Vietnam: Quang Nam Province, Hoi An City, Cu Lao Cham Island, a stream near Bai Huong, 15°56'22''N 108°31'12''E, coll. Do Van Tu, 9 May 2017; 3 males, cl 3.6–4.0, 2 females, cl 4.2–4.4 (ZMB 30309), Vietnam: Quang Nam Province, Hoi An City, Cu Lao Cham Island, a small stream ca. 3 km to Bai Huong, 15°56'39''N 108°30'45'' E, coll. Do Van Tu, 9 May 2017.
Cephalothorax and cephalic appendages. Carapace length 3.5–4.8 mm. Rostrum straight, slightly bent downwards, reaching to middle or the end of second segment of antennular peduncle, 0.38–0.46 (median 0.43) times as long as carapace, rostral formula: 4–5+9–12/3–5 (n = 10), teeth normal (Fig.
Abdominal somites, telson and uropods. Sixth abdominal somite 0.5–0.6 (median 0.57) times length of carapace, 1.50–2.0 (median 1.67) times as long as fifth abdominal somite, 0.86–1.05 (median 1.0) times length of telson. Telson length 2.1–2.75 (median 2.44) times as long as proximal width, distal margin triangular, terminating in a short median projection, with 5–6 pairs of dorsal spiniform setae and one pair of dorso-subdistal spiniform setae; distal end with 4 pairs of spiniform setae, lateral pair slightly shorter than intermediate pairs (Fig.
Pereiopods. Epipod present on first four pereiopods. First pereiopod short, robust, reaching beyond end of basal segment of antennular peduncle; chela 2.0–2.2 (median 2.0) times as long as wide, 1.33–1.67 (median 1.42) times length of carpus; tips of fingers rounded, without hooks; dactylus slightly longer than palm, 1.0–1.1 (median 1.1) times as long as palm in males and shorter than palm, 0.8–0.86 (median 0.83) times as long as palm in females; carpus excavated anteriorly, 1.5–1.88 (median 1.65) times as long as wide, 0.67–0.8 (median 0.8) times length of merus; merus 2.14–3.0 (median 2.5) times as long as wide, longer than ischium (Fig.
Pleopods. Endopod of male first pleopod extending to 0.6 times length of exopod, rectangular in shape, anterior part folded backwards, 2.0–2.73 (median 2.53) times as long as proximal width, inner margin concave, outer margin concave or slightly straight, rounded distally, long plumose setae on outer and distal margins, medium-length setae on inner margin; with appendix interna exceeding terminal margin of endopod by 0.3 of its length (Fig.
Colouration. Body yellowish, few irregular small black spots present on ventrolateral parts of carapace and abdominal somites (Fig.
Cu Lao Cham, in north-central Vietnam (Fig.
Species | Egg size (mm) | Distribution in Vietnam |
Caridina cantonensis Yu, 1938 | 0.85–0.95 × 0.55–0.6 | Only occurs on Cu Lao Cham, a small Island in north-central Vietnam |
Caridina lanceifrons Yu, 1936 | 0.8–0.9 × 0.5–0.6 | Widely distributed in North Vietnam |
Caridina serrata Stimpson, 1860 | 1.0 × 0.6 | Only occurs on Cu Lao Cham Island |
Neocaridina palmata palmata (Shen, 1948) | 1.0–1.1 × 0.7 | Confined to the northeast of Vietnam |
Caridina lanceifrons Yu, 1936: 89, figs. 4–7. [Type locality: near the lighthouse at Hai-kiu-sche in the salt water; neotype locality: pond near Qiongshan City, Haikou, Hainan, China (designation by
Caridina lanceifrons —
Caridina flavilineata Dang, 1975: 70–71, fig. 5. [Type locality: Nam Ha = Ha Nam and Nam Dinh Provinces, northern Vietnam];
Caridina vietriensis Dang & Do, 2007: 9–10, figs. 7–8. [Type locality: Viet Tri City, Phu Tho Province, Vietnam].
Caridina pseudoflavilineata Do & Dang, 2010: 31–34, figs. 3–4. [Type locality: Hai Van mountain pass, Thua Thien Hue Province, Vietnam].
Material examined for description. 1 female, cl 3.5 (ZMB 33800), Vietnam: Nam Dinh Province, Nghia Hung District, Nghia Son Commune, Quan Lieu, 20°11'25.619''N 106°10'49.109'' E, [= type locality of Caridina flavilineata Dang, 1975], coll. Do Van Tu, 31 May 2020; 2 males, cl 3.5–3.6, 3 females, cl 4.6–5.6 (ZMB 33823), Vietnam: Vinh Phuc Province, Vinh Tuong District, 21°15'03.0"N 105°26'48.6"E, [= type locality of Caridina vietriensis Dang & Do, 2007], coll. Do Van Tu, 19 July 2020; 5 males, cl 2.6–5.0, 12 females, cl 2.8–5.3 (ZMB 30264), Vietnam: Da Nang City, Lang Van Commune, 16°10'4''N 108°8'32''E, [= near the type locality of Caridina pseudoflavilineata Do & Dang, 2010], coll. Do Van Tu, 5 May 2017.
Cephalothorax and cephalic appendages. Carapace length 2.6–5.3 mm. Rostrum straight, reaching near to or slightly beyond end of antennular peduncle, 0.45–0.96 (median 0.6) times as long as carapace, rostral formula: 4–6+10–16/1–5 (n = 10), teeth normal (Fig.
Abdominal somites, telson and uropods. Sixth abdominal somite 0.38–0.62 (median 0.44) times length of carapace, 1.36–1.64 (median 1.62) times as long as fifth abdominal somite, 0.6–1.0 (median 0.86) times length of telson. Telson length 2.33–3.85 (median 2.81) times as long as proximal width, distal margin triangular, terminating in a short median projection, with 5–6 pairs of dorsal spiniform setae and one pair of dorso-subdistal spiniform setae; distal end with 4–5 pairs of spiniform setae, lateral pair longer than intermediate pairs (Fig.
Pereiopods. Epipod present on first four pereiopods. First pereiopod short, robust, reaching to distal end of eyestalk; chela 1.89–2.4 (median 2.19) times as long as wide, 1.24–2.09 (median 1.44) times length of carpus; tips of fingers rounded, with hook; dactylus slightly longer than palm, 1.0–1.33 (median 1.11) times as long as palm; carpus excavated anteriorly, 1.22–2.0 (median 1.85) times as long as wide, 0.65–0.86 (median 0.8) times length of merus; merus 2.57–3.25 (median 2.86) times as long as wide, longer than ischium (Fig.
Pleopods. Endopod of male first pleopod extending to 0.4 times length of exopod, subtriangular in shape, 2.09–2.88 (median 2.32) times as long as proximal width, rounded distally, long plumose setae on outer and distal margins, medium-length setae on inner margin; with appendix interna exceeding terminal margin of endopod by 0.5 times its length (Fig.
Colouration. Body yellowish (Fig.
This species is widely distributed in northern Vietnam (no further south than Quang Nam Province in central Vietnam). In China, the species were found in Fujian, Guangdong, Guangxi, Hainan and Hunan (
This species inhabits mountain streams and rivers. We could not collect any specimens of this species from estuarine environments. In addition, based on egg-size (Table
The populations in Vietnam showed no significant difference when compared to the original description of Caridina lanceifrons Yu, 1936 in
Three species described from Vietnam have been considered synonyms of Caridina lanceifrons:
According to
Caridina serrata Stimpson, 1860: 29. [Type locality: hill above Bekhers, Hong Kong Island, Hong Kong, China; neotype designation by
Caridina serrata —
non Caridina serrata serrata — Dang in
non Caridina serrata —
Material examined for description. 10 males, cl 3.1–4.7, 5 females, cl 4.0–4.6 (ZMB 30306), Vietnam: Quang Nam Province, Hoi An City, Cu Lao Cham Island, a small stream running into the reservoir, 15°56'34.9''N 108°31'22.7''E, coll. Pham The Cuong, 10 May 2017.
Cephalothorax and cephalic appendages. Carapace length 3.1–4.7 mm. Rostrum short, straight or slightly curved downwards, reaching to the end of basal segment of antennular peduncle, 0.38–0.46 (median 0.43) times as long as carapace, rostral formula: 0–4+3–10/0–2 (n = 10), teeth normal (Fig.
Abdominal somites, telson and uropods. Sixth abdominal somite 0.41–0.49 (median 0.42) times length of carapace, 1.44–1.67 (median 1.52) times as long as fifth abdominal somite, 0.85–1.0 (median 0.9) times length of telson. Telson length 2.14–2.5 (median 2.36) times as long as proximal width, distal margin triangular, terminating in a short median projection, with 4–5 pairs of dorsal spiniform setae and one pair of dorso-subdistal spiniform setae; distal end with 4 pairs of spiniform setae, lateral pair slightly longer than intermediate pairs (Fig.
Pereiopods. Epipod present on first four pereiopods. First pereiopod short, robust, reaching beyond end of basal segment of antennular peduncle; chela 1.69–2.0 (median 1.92) times as long as wide, 1.39–1.56 (median 1.47) times length of carpus; tips of fingers rounded, with hook; dactylus shorter than palm, 0.67–0.92 (median 0.75) times as long as palm; carpus excavated anteriorly, 1.67–1.80 (median 1.73) times as long as wide, 0.78–0.9 (median 0.79) times length of merus; merus 2.11–2.56 (median 2.22) times as long as wide, longer than ischium (Fig.
Pleopods. Endopod of male first pleopod extending to 0.7 times length of exopod, sub-rectangular in shape, 2.45–2.75 (median 2.6) times as long as proximal width, inner margin concave, outer margin slightly convex, rounded distally, long plumose setae on outer and distal margins, medium-length setae on inner margin; with appendix interna exceeding terminal margin of endopod by 0.4 times its length (Fig.
Caridina serrata Stimpson, 1860 was recorded from Hong Kong Island only by
Although this species up to now was only recorded from streams on small islands (which are on the continental shelf, i.e. would have been connected to the mainland during glacial maxima; see, for example,
Caridina palmata Shen, 1948: 120, plate 12, fig. j. [Type locality: Sha-ping-pa, Chungking, China].
Caridina elongata Shen, 1948: 121, plate 13, figs. a–e. [Kweilin, China]
Caridina denticulata vietnamensis Dang, 1967: 157, fig. 4. [Cao Bang and Lang Son provinces, Vietnam].
Caridina vietnamensis —
Caridina denticulata —
Neocaridina palmata palmata —
Neocaridina palmata —
Neocaridina vietnamensis —