Species description:

THE RAFFLES BULLETIN OF ZOOLOGY 2007 55(2): 311–320
Date of Publication: 31 Aug.2007
ATYID SHRIMPS FROM LAKE POSO, CENTRAL SULAWESI, INDONESIA WITH DESCRIPTION OF A NEW SPECIES (CRUSTACEA: DECAPODA: CARIDEA)

Yixiong Cai, Daisy Wowor

ABSTRACT – The taxonomy of the freshwater shrimps of the Family Atyidae from Lake Poso, central Sulawesi, is revised on the basis of type material and fresh collections. Caridina sarasinorum Schenkel, 1902, and C. ensifera Schenkel, 1902, are redescribed in detail and lectotypes for both species are designated. Caridina acutirostris Schenkel, 1902, which was originally described based on a single female specimen, was not found during recent fi eld collections. One new species, C. longidigita, is also described. Four species of Caridina are now known from Lake Poso.
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Epibiontic communities on the freshwater shrimp Caridina ensifera (Crustacea, Decapoda, Atyidae) from Lake Poso (Sulawesi, Indonesia)
Gregorio Fernandez‐Leborans & Kristina Von Rintelen
Pages 2891-2917 | Accepted 05 Nov 2007, Published online: 31 Dec 2007 Download citation http://doi.org/10.1080/00222930701787871

The epibiont communities of the freshwater shrimp Caridina ensifera, endemic to Lake Poso (Sulawesi, Indonesia), were analysed for the first time based on their morphological and biometrical characteristics and taxonomic position. Seven ciliated protozoans and a rotifer were examined: three suctorian ciliate protozoan species (Acineta sulawesiensis, Podophrya maupasi, and Spelaeophrya polypoides), three peritrichs (Zoothamnium intermedium, Vorticella globosa, and Cothurnia compressa), a haptorid (Amphileptus fusidens), and the rotifer species Embata laticeps. A mean number of 314.6 epibionts was found per shrimp specimen. The distribution of the epibiont species on the surface of the basibiont was recorded, to allow calculation of the density on the different colonized individuals of C. ensifera and on each anatomical unit of the shrimp. The most abundant species, Zoothamnium intermedium and Acineta sulawesiensis, were also the ones most widely distributed. The statistical analysis showed that Zoothamnium, Acineta, Podophrya, and Embata were the epibiont genera most widely distributed on the basibiont, and the pairs of epibiont genera Zoothamnium–Embata, Podophrya–Acineta, Spelaeophrya–Amphileptus, and Cothurnia–Vorticella followed a similar pattern of distribution. There was a significant difference between the distribution patterns of the different epibiont species on the shrimp. The analysis of the densities of the epibionts throughout the longitudinal axis of the shrimp showed a gradient from the anterior to the posterior end of the body, and a significantly different distribution of each epibiont species. Their colonization follows a certain pattern of behaviour, the species occupying the available substratum, with particular requirements of each functional group, but with a trend resulting in equilibrium among species and groups, compensating for diversity and density. The possible adaptations of the epibionts, as well as the colonization patterns are discussed.

Biodiversity and distribution of epibiontic communities on Caridina ensifera (Crustacea, Decapoda, Atyidae) from Lake Poso: comparison with another ancient lake system of Sulawesi (Indonesia)
Acta Zoologica (Stockholm) 91: 163–175 (April 2010) doi: 10.1111/j.1463-6395.2009.00395.x
Gregorio Fernandez-Leborans and Kristina von Rintelen, 2010 (PDF)

The epibiont communities of the shrimp Caridina ensifera, endemic to Lake Poso (Sulawesi, Indonesia), were analysed. Most of the epibiont species were ciliated protozoa belonging to three suctorian genera (Acineta, Podophrya and Spelaeophrya), three peritrich genera (Zoothamnium, Vorticella and Cothurnia), and a haptorid genus (Amphileptus). There was also a rotifer epibiont of the genus Embata. Epibionts were identified to species level. There were 14 to 1114 epibionts per shrimp. The distribution of the epibiont species on the surface of the basibiont was recorded, calculating the number on the different colonized individuals of C. ensifera. The most abundant species, Zoothamnium intermedium and Acineta sulawesiensis, were also the most widely distributed. There was a significant difference between the spatial distributions of the different epibiont species. The analysis of the number of the epibiont species throughout the anteroposterior axis of the shrimp showed a gradient from the anterior to the posterior end of the body. Data from Lake Poso were compared with those of the Malili lake system (Sulawesi), obtained from its endemic shrimp, Caridina lanceolata. Lake Poso had the highest mean diversity, while Lake Mahalona showed the highest maximum diversity. All lakes were correlated with respect to the mean number of epibionts on the anatomical units of the shrimp, which showed a similar general distribution. The distributions of the different epibiont species were compared between the lakes. The possible adaptations of the epibionts as well as the colonization patterns were discussed. From the statistical results and the analysis of the distributions, we propose that in these communities epibiont species have a pattern of colonization in which they follow a behaviour as a whole; each species has a differential distribution, with the species occupying the available substratum with the particular requirements of each functional group, but there is a trend towards maintaining an equilibrium among species and groups, compensating for diversity and number of individuals. In all lakes there was an epibiont distribution model comprising the maintenance of an anteroposterior axis gradient, which was supported by the fluctuation in diversity and number of individuals of the different functional groups of epibiont species. The functional role of the different groups of species seems to tend towards sustainability with little global variation among the lakes.

Molecular Phylogenetics and Evolution 45 (2007) 1033–1041
Molecular phylogeny and diversification of freshwater shrimps (Decapoda, Atyidae, Caridina) from ancient Lake Poso (Sulawesi, Indonesia)—The importance of being colourful
Kristina von Rintelen *, Thomas von Rintelen, Matthias Glaubrecht
Museum of Natural History, Humboldt University Berlin, Invalidenstrasse 43, 10115 Berlin, Germany
Received 2 April 2007; revised 23 June 2007; accepted 1 July 2007

Abstract Ancient Lake Poso on the Indonesian island Sulawesi hosts a highly diverse endemic fauna, including a small species flock of atyid Caridina shrimps, which are characterized by conspicuous colour patterns. We used a mtDNA based molecular phylogeny to test the assumption of a monophyletic origin and intralacustrine radiation of the species flock and to assess the species specificity of some colour morphs. Our data reveal a rapid radiation of Caridina in the entire Poso drainage system, but provide no strong evidence for a monophyletic radiation of the lake species. Nevertheless each lacustrine species shows a varying degree of substrate or trophic specialization, usually considered a hallmark of adaptive radiation. Two distinct colour forms previously attributed to a single species, C. ensifera, lack distinguishing qualitative morphological characters, but are shown to be two different species. In contrast, morphologically rather distinct lake species lacking specific colour patterns may be hybridizing with riverine taxa. These results suggest that colour may play a similar role in species recognition and possibly speciation in ancient lake Caridina as hypothesized, e.g. for some African cichlids.

Molecular Evidence for High Frequency of Multiple Paternity in a Freshwater Shrimp Species Caridina ensifera
Gen Hua Yue, Alex Chang; Published: September 14, 2010 https://doi.org/10.1371/journal.pone.0012721

Abstract
Background
Molecular genetic analyses of parentage provide insights into mating systems. Although there are 22,000 members in Malacostraca, not much has been known about mating systems in Malacostraca. The freshwater shrimp Caridina ensifera blue, is a new species belonging to Malacostraca which was discovered recently in Sulawesi, Indonesia. Due to its small body size and low fecundity, this species is an ideal species to study the occurrence and frequency of multiple paternity and to understand of how the low fecundity species persist and evolve.

Methodology/Principal Findings
In this study, we developed four polymorphic microsatellites from C. ensifera and applied them to investigate the occurrence and frequency of multiple paternity in 20 C. ensifera broods caught from Lake Matano, Sulawesi. By genotyping the mother and all offspring from each brood we discovered multiple paternity in all 20 broods. In most of the 20 broods, fathers contributed skewed numbers of offspring and there was an apparent inverse correlation between reproductive success of sires and their relatedness to mothers.

Conclusions/Significance
Our results in combination with recent reports on multiple paternity in crayfish, crab and lobster species suggests that multiple paternity is common in Malacostraca. Skewed contribution of fathers to the numbers of offspring and inverse correlation between reproductive success of sires and their relatedness to mothers suggest that sperm competition occurred and/or pre- and postcopulatory female choice happen, which may be important for avoiding the occurrence of inbreeding and optimize genetic variation in offspring and for persistence and evolution of low fecundity species.