Yixiong Cai

Yixiong Cai
National Parks Board · National Biodiversity Centre

Doctor of Philosophy

About

118
Publications
63,180
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1,798
Citations
Citations since 2016
35 Research Items
966 Citations
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200

Publications

Publications (118)
Chapter
This paper established a hydrological baseline for a small Dermawan forest catchment (19 ha) in Singapore. Its stream is habitats for critically endangered crab species; thus, immediate protection plans are required. Through topographical and hydrological surveys, it was observed that the stream corridor is facing stress issues of bank slope erosio...
Article
Full-text available
Functional traits offer generalizability to the prediction of ecosystem processes such as production, and community-weighted mean trait values are increasingly used for such predictions. However, the underlying causal direction between traits and ecosystem processes are often indirect and sometimes even tenuous. In this study, we aimed to uncover u...
Article
We investigated processes contributing to periodic acidification events in headwater streams of Nee Soon Forest Catchment (NSFC) in Singapore by monitoring hydrochemical changes in response to rainfall inputs. Stream chemistry response to most rainfall events was characterised by decreases in pH from means ranging from 5.1 to 5.3 to below 4.8 to 5....
Article
The atyid shrimps of Caridina nilotica species group from China are reviewed. Taxonomic diagnosis and discussions are given to three species so far known from China, viz. Caridina gracilipes De Man, 1892, Caridina macrophora Kemp, 1918 and Caridina elongapoda Liang & Yan, 1977. Detailed morphological description and illustrations are provided for a...
Article
Decomposition is a key ecosystem function, and the rate of decomposition in forests affects their carbon storage potentials. Processes and factors determining leaf litter decomposition rates in dry‐land and temperate forests are well understood, but these are generally poorly studied in tropical wetland forests, especially freshwater swamp forests...
Article
A total of 24 soil samples, including 4 subsurface, 34 water samples and 17 sets of hydrological survey data were collected in a soil investigation and hydrological survey campaign from August 2017 to September 2018 at a small Dermawan forest catchment, Singapore. The study was to understand and evaluate the catchment’s soil and stream status throu...
Article
Full-text available
A new species of landlocked freshwater shrimp, Neocaridina fonticulata sp. n. (Atyidae), is described from Kenting, Hengchun Peninsula, Pingtung County, southern Taiwan. This new species can be distinguished from its congeners by rostrum structure, pereiopods, and male first and second pleopods. The molecular evidence of mitochondrial cytochrome ox...
Article
Seven new atyid shrimp species of the genus Caridina H. Milne Edwards, 1837 are described from southern China: C. longshan sp. nov., C. alu sp. nov., C. spinicrus sp. nov., C. beiliu sp. nov., C. jiangkou sp. nov., C. guilin sp. nov. and C. laticarpalis sp. nov. Descriptions and figures for all taxa are provided, and taxa are compared with their cl...
Article
Full-text available
Freshwater species often show high levels of endemism and risk of extinction owing to their limited dispersal abilities. This is exemplified by the stenotopic freshwater crab, Johora singaporensis which is one of the world's 100 most threatened species, and currently inhabits less than 0.01 km² of five low order hill streams within the highly urban...
Article
Full-text available
Nee Soon freshwater swamp forest is the last remaining primary freshwater swamp forest left in Singapore and it contains a rich diversity of native and locally threatened fauna. As native terrestrial snails and slugs are poorly studied and understood in Nee Soon freshwater swamp forest, an extensive survey was conducted to establish their current s...
Article
Full-text available
The current paper acts as a summary to the “Nee Soon Swamp Forest biodiversity and hydrology baseline studies project”, including results published previously and the results from papers of the current volume. Overall, flora and fauna surveys indicate healthy and diverse plant, fish and aquatic macroinvertebrate communities in Nee Soon freshwater s...
Article
Full-text available
In this study, the authors first obtained the mitochondrial genome of Somanniathelphusa boyangensis. The results showed that the mitochondrial genome is 17,032bp in length, included 13 protein-coding genes, 2 rRNAs genes, 22 tRNAs genes and 1 putative control region, and it has the characteristics of the metazoan mitochondrial genome A+T bias. All...
Data
Primers used in the present study. (DOCX)
Data
Brachyura species included in the present divergence time estimation. (DOCX)
Data
Brachyura species included in the present phylogenetic analysis. (DOCX)
Data
The base composition in different regions of mitochondrial genome of Somanniathelphusa boyangensis. (DOCX)
Article
In the present study, we determined the complete mitochondrial genome of Huananpotamon lichuanense (Decapoda: Brachyura) for the first time. The genome is 15,380bp in length and typically consists of 37 genes. When the gene order was compared to the ancestral crustacean type, two tRNA genes (tRNAHis and tRNAGln) were rearranged in H. lichuanense, a...
Article
Full-text available
Hsi-Te Shih, Yixiong Cai, Nobuaki Niwa, and Yasuhiko Nakahara (2017) A new species of landlocked freshwater shrimp, Neocaridina ikiensis (Decapoda: Caridea: Atyidae), is described from Iki Island, Kyushu, Japan, based on morphological and molecular evidence. This new species can be distinguished from its congeners by a suite of characters, includin...
Book
Full-text available
Aquatic macroinvertebrates and lower vertebrates were surveyed from the last remaining freshwater swamp forest in Singapore. Ecological data was collated from three years of field work. This book is a guide to the macroinvertebrates and the fish of the Nee Soon Swamp Forest, with identification keys provided as well.
Chapter
The critically endangered Singapore freshwater crab, Johora singaporensis, is among the 100 most threatened species in the world. The species is endemic to Singapore and known from only a few hill stream localities. Conservation approaches so far have largely focused on basic descriptive research into the animal’s taxonomy, autecology and distribut...
Chapter
The Nee Soon Swamp Forest (NSSF) (87 ha) in Singapore houses a rich diversity of fauna and is the only area of primary freshwater swamp left on that island. The current study investigates the diversity and population changes of the freshwater decapod fauna of the NSSF with the aim of facilitating future conservation actions. Surveys were carried ou...
Article
Full-text available
A new species of stygobitic freshwater prawn, Macrobrachium spelaeus from Tham Phra Wang Daeng, Pitsanulok Province, in northern Thailand, is described and illustrated in detail. Morphological comparisons with allied epigean species M. dienbienphuense and known stygobitic congener M. poeti are given. The new species is characterised by its reduced...
Article
Gelidioid specimens from Singapore were analyzed using sequences of cox1 and rbcL to identify the species. Both datasets revealed the presence of four species: Gelidiella acerosa, Pterocladiella bartlettii, Pterocladiella caerulescens and Gelidium sentosaense sp. nov., described here. Gelidium sentosaense formed small tufts up to 1 cm high and occu...
Article
Full-text available
The Nee Soon Swamp Forest is the last remaining primary freshwater swamp forest in Singapore and contains almost half of its native and threatened freshwater fauna. As the last in-depth fauna study of freshwater fishes in NSSF was published nearly two decades ago, eight series of surveys were carried out over a year to document the species currentl...
Article
Full-text available
Two specimens of the caecilian, Ichthyophis paucisulcus, were observed in a hill stream at the eastern part of the Bukit Timah Nature Reserve, Singapore. This discovery provides valuable insight to the behaviour and habitat preferences of this locally rare and elusive species.
Article
Full-text available
We present the first global assessment of extinction risk for a major group of freshwater invertebrates, caridean shrimps. The risk of extinction for all 763 species was assessed using the IUCN Red List criteria that include geographic ranges, habitats, ecology and past and present threats. The Indo-Malayan region holds over half of global species...
Article
Plants of the red algal genus Parviphycus are typically diminutive and often occur in mixed stands with other turf species, leading to considerable difficulty in locating them in the field. Once sorted, identification to genus and species is challenging because of their lack of conspicuous diagnostic features. Examination of the type specimen and f...
Article
Full-text available
A previously unknown population of the Singapore freshwater crab (Johora singaporensis), was discovered in a new hill-stream locality in a restricted area in Bukit Gombak, Singapore. This discovery highlights the value of hill-stream habitats and the important role that restricted security areas play in the protection of local biodiversity in Singa...
Article
Full-text available
A population of the Singapore freshwater crab, Johora singaporensis, was discovered at a newly located hill-stream site in the eastern part of the Bukit Timah Nature Reserve. This discovery highlights the value of hill-stream habitats and their important role in the protection of endemic and endangered aquatic fauna in Singapore.
Article
The atyid shrimps of Hainan Island, China, are reviewed. A taxonomic synopsis is given for the seven species of Caridina so far known from Hainan, including two new records, C. clinata and C. elongapoda, and one new species, Caridina baoting sp. nov. A detailed morphological description and illustrations are provided for the new species. Caridina b...
Article
Full-text available
Cai, Y. and Teo, S.L.M. 2012. Synidotea poorei, a new isopod from the fouling community of Singapore (Valvifera, Idoteidae). Memoirs of Museum Victoria 69: 237–243. Synidotea poorei new species (Idoteidae) is described from fouling community on navigational buoys and jetties in Singapore waters. It belongs to the S. hirtipes species group. The new...
Article
Full-text available
Atyid freshwater shrimps are globally distributed and form an important part of freshwater ecosystems, particularly in the tropics and subtropics. Despite their widespread distribution and ecological importance, their phylogenetic relationships are largely unresolved. Here we present the first comprehensive molecular phylogeny of the Atyidae invest...
Poster
Full-text available
The evolution of troglobionts has fascinated scientists since Darwin’s time. A high number of cave-dwelling animals are well studied today, among these several freshwater organisms, e.g. fishes or crustaceans. The freshwater shrimp family Atyidae (Crustacea, Decapoda, Caridea) also has several subterranean representatives worldwide. Whereas the tro...
Article
Caridina typus var. brevirostris Roux is shown to be specifically different from Caridina typus H. Milne Edwards, 1837. A new name Caridina jeani is thus proposed for the species as the name Caridina brevirostris is preoccupied by C. brevirostris Stimpson, 1860. The species is re-described and illustrated in detail based on syntypic specimens. It d...
Article
Atydina, new genus, is established for Caridina atyoides Nobili, 1900, so far known only from two islands in Indonesia. It is characterized by the robust third and fourth pereiopods, and an inflated cylindrical appendix masculina on the male second pleopod. The new genus is compared to the related genera Atyopsis Chace, 1983 and Caridina H Milne Ed...
Article
Caridina typus var. brevirostris Roux is shown to be specifically different from Caridina typus H. Milne Edwards, 1837. A new name Caridina jeani is thus proposed for the species as the name Caridina brevirostris is preoccupied by C. brevirostris Stimpson, 1860. The species is re-described and illustrated in detail based on syntypic specimens. It d...
Article
Atydina, new genus, is established for Caridina atyoides Nobili, 1900, so far known only from two islands in Indonesia. It is characterized by the robust third and fourth pereiopods, and an inflated cylindrical appendix masculina on the male second pleopod. The new genus is compared to the related genera Atyopsis Chace, 1983 and Caridina H Milne Ed...
Article
A new species of freshwater shrimps of the genus Parisia from Papua New Guinea was described. The new species with well-developed eyes, is different from P. macrophthalma from Madagascar in its much shorter and unarmed rostrum. It could be easily separated from P. deharvengi from Sulawesi by the well-developed eyes and having more spines on dactylu...
Article
Freshwater prawns of the genus Macrobrachium are free-living decapod crustaceans that are commonly encountered in tropical streams and lakes. We present a molecular phylogenetic analysis of the diverse Southeast and East Asian fauna based on >3 kb sequence data from three nuclear and two mitochondrial markers for almost 50% of the described fauna....
Article
Full-text available
The ancient lakes of the Indonesian island Sulawesi harbour two endemic species flocks of the freshwater shrimp genus Caridina (Crustacea: Decapoda: Atyidae). One of them forms the largest radiation within the genus. Species from both lake systems evolved under similar extrinsic conditions and show some parallel patterns, e.g. the development of un...
Article
The present study reports on collections of hypogean freshwater atyid shrimps of the genera Caridina Milne Edwards, 183719. Milne Edwards , H. 1837 . Histoire naturalle des Crustacés, Comprenant l'Anatomie, la Physiologie et la Classification de ces Animaux , Vol. 2 , 1 – 532 . Paris (France) : Libraire Encyclopedique de Roret . View all references...
Article
The taxonomy of freshwater shrimps of the family Atyidae from the Malili lake system, Central Sulawesi, is partially revised based on museum materials and fresh collections. Caridina lanceolata, C. masapi, C. spinata and C. loehae are redescribed and neotypes are designated as all type materials for these species are no longer extant. Two new speci...
Article
The taxonomy of freshwater shrimps of the family Atyidae from the Malili lake system, Central Sulawesi, is partially revised based on museum materials and fresh collections. Caridina lanceolata, C. masapi, C. spinata and C. loehae are redescribed and neotypes are designated as all type materials for these species are no longer extant. Two new speci...
Article
Full-text available
The troglobitic freshwater shrimp genus Edoneus Holthuis, 1978, is revised on the basis of a fresh collection from several caves in Luzon, the Philippines, as well as previously studied collections deposited at the National Museum of Natural History, Leiden. The revised genus is characterized by the absence of an arthrobranch on the fi rst pereiopo...
Article
Full-text available
The epigean and hypogean freshwater shrimps from Bohol Island, central Philippines, collected during various speleological expeditions by the Philippine, Slovenian and Singaporean scientists between 1995 and 2000 are reported here. The material contains 25 species of caridean shrimps in two families. The Atyidae are represented by 16 species from f...
Article
Two species of atyid shrimps are reported from a cave in western Madagasacar, namely Caridina isaloensis and Caridina steineri, a new species. Morphology of both species is described and illustrated in detail. Morphological comparisons with their allied species from Madagascar are highlighted.
Data
FIGURE 1. Caridina lanceolata, A. cephalothorax and cephalic appendages, B. telson, C. distal portion of telson, D. scaphocerite, E. mandible, F. first maxilliped, G. second maxilliped, H. third maxilliped, I. preanal carina. Scales: A = 1 mm; B, D – I = 0.5 mm; C = 0.2 mm. (male, cl 3.0 mm, ZRC)
Data
FIGURE 5. Caridina masapi, A. telson, B. distal portion of telson, C. first pereiopod, D. second pereiopod, E. third pereiopod, F. dactylus of third pereiopod, G. fifth pereiopod, H. dactylus of fifth pereiopod, I. diaeresis. Scales: A, C – E, G = 0.5 mm; B, F, H, I = 0.2 mm. (ovigerous female, cl 3.8 mm, egg sized 0.9 x 0.5 mm, MK 95 - 3, Sulawesi...
Data
FIGURE 8. Caridina mahalona, new species A, I. cephalothorax and cephalic appendages, B. telson, C. distal portion of telson; D. scaphocerite, E. mandible, F. maxillula; G. maxilla, H. first maxilliped, I. second maxilliped, J. third maxilliped, K. diaeresis. Scales: A, L = 1 mm; B, E – J = 0.5 mm; C, K = 0.2 mm. (A – K, paratype, male, cl 3.9 mm,...
Data
FIGURE 2. Caridina lanceolata, A. first pereiopod, B. second pereiopod, C. third pereiopod, D. fifth pereiopod, E. dactylus of third pereiopod, F. dactylus of fifth pereiopod, G. endopod of male first pleopod, H. appendix masculina and appendix interna of male second pleopod, I. uropodal diaeresis. Scales: A – D = 0.5 mm; E, F = 0.1 mm; G, H = 0.2...
Data
FIGURE 6. Caridina spinata, A. cephalothorax and cephalic appendages, lateral view, B. distal portion of telson, C. preanal carina, D. telson, E. scaphocerite, F. first pereiopod, G. second pereiopod, H. third pereiopod, I. Fifth pereiopod, J. dactylus of third pereiopod, K. dactylus of fifth pereiopod, L. diaeresis. Scales: A, D, E = 1 mm; B, L =...
Data
FIGURE 3. Caridina woltereckae, new species A. cephalothorax and cephalic appendages, B. telson, C. distal portion of telson, D. scaphocerite, E. mandible, F. maxillula, G. maxilla, H. first maxilliped, I. second maxilliped, J. third maxilliped, K. first pereiopod, L. second pereiopod, M. third pereiopod, N, O. dactylus of third pereiopod, P. fifth...
Data
FIGURE 4. Caridina masapi, A – B, cephalothorax and cephalic appendages, C. antennular peduncle, D, scaphocerite, E. mandible, F. maxillula, G. first maxilliped, H. second maxilliped, I. third maxilliped. Scales: A, B = 1 mm; C – I = 0.5 mm. (A, C – I, ovigerous female, cl 3.8 mm, egg sized 0.9 x 0.5 mm, B. female, cl 3.7 mm, MK 95 - 3, Sulawesi)
Data
FIGURE 7. Caridina loehae, A. cephalothorax and cephalic appendages, B. cephalothorax and cephalic appendages, C. telson, D. distal portion of telson, E. scaphocerite, F. mandible, G. maxillula, H. maxilla, I. first maxilliped, J. second maxilliped, K. third maxilliped, L. first pereiopod, M. second pereiopod, N. third pereiopod, O. dactylus of thi...
Data
FIGURE 9. Caridina mahalona, new species. A. cephalothorax and cephalic appendages, B. first pereiopod, C. second pereiopod, D. third pereiopod, E. dactylus of third pereiopod, F. fifth pereiopod, G. dactylus of fifth pereiopod, H. endopod of male first pleopod, I. appendix masculina and appendix interna of male second pleopod. Scales: A = 1 mm; B...
Chapter
Full-text available
Freshwater caridean shrimps account for approximately a quarter of all described Caridea, numerically dominated by the Atyidae and Palaemonidae. With the exception of Antarctica, freshwater shrimp are present in all biogeographical regions. However, the Oriental region harbours the majority of species, whilst the Nearctic and western Palaearctic ar...
Article
Full-text available
Two new species of land-locked shrimp, Neocaridina saccam and N. ketagalan (Decapoda: Caridea: Atyidae), are described from Tainan, southwestern Taiwan, and Taipei, northern Taiwan, respectively. Based on morphological and molecular (mitochondrial 16S rRNA and cytochrome oxidase I genes) evidence, both can be distinguished from their congeners. A s...
Article
Re‐examination of the syntypes of Caridina gracilirostris De Man, 18929. De Man , J. G. 1892 . “ Decapoden des Indischen Archipels. ” . In Zoologische Ergebnisse einer Reise in Niederlandisch Ost‐Indien Edited by: Weber , M . Vol. 2 , 265 – 527 . Plates 15–29 View all references, shows that the type series is composed of three species. These three...