广东米虾属一新种与一新纪录种记述(十足目,匙指虾科)

报道了采自广东的十足目匙指科米虾属1新种,清远米虾Caridina qingyuanensis sp. nov..新种与近似种华南米虾的主要区别在于雄性第1附肢内肢与内附肢的形状不同,第3～5对步足各节上刺的着生位置与数量不同,尾外肢横缝刺的数量少.首次报道了秉氏米虾Caridina pingi Yu,1938在广东的分布.     

云南米虾属一新种(十足目,匙指虾科)

记述了采集于云南蒙自匙指虾科米虾属1新种,贫齿米虾Caridina paucidentata sp.nov..文中详细描述了其形态特征,同时附特征图.新种和近似种蒙自米虾的主要区别在于前者额角背缘齿少,仅1～3个.模式标本保存于上海水产大学.     

Molecular phylogeny and diversification of freshwater shrimps (Decapoda, Atyidae, Caridina) from ancient Lake Poso (Sulawesi, Indonesia)--the importance of being colourful

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.     

Scanning electron microscope studies on the internal structures of the stomachs of some atyid and palaemonid prawns

Abstract

This paper deals with the internal structures of the stomachs of the atyid prawns Caridina africana, Atyaephyra desmaresti desmaresti and A. d. orientalis and of the palaemonid prawns Palaemon elegans and Palaemonetes antennarius. The various regions of the stomach are described and discussed in relation to diet.     

Effects of the Tropical Freshwater Shrimp Caridina weberi (Atyidae) on Leaf Litter Decomposition1

Effects of feeding by atyid shrimp, Caridina weberi, on the rate of decomposition of leaf litter were studied in the Opunohu River, Moorea, French Polynesia. In a laboratory feeding experiment shrimp consumed microbially conditioned Hibiscus leaves, but in a field study shrimp did not affect the rate of decomposition of leaf litter. In this system, the rate of decomposition was influenced more by water discharge or by microbial activity than by shrimp.     

湖南淡水虾类两新种(十足目:匙指虾科:米虾属)

报道湖南省淡水匙指虾科米虾属两新种。窄肢米虾Caridina angustipes sp.now.与保靖米虾C.baojingensis Guo,He et Bai,1992近似,但新种额角长,上缘具15-27齿,下缘具3-6齿;雄性第一附肢内肢的内缘平直。棒肢米虾C.clavipes sp.nov.略似窄肢米虾C.angustipes,但目前雄性第一附肢内肢末端尖细,内缘刺少;雄性第二附肢雄附肢短而细,内缘仅具1刺,末端仅具4刺。正模标本保存在上海水产大学,副模标本保存在佛山科学技术学院。     

Stable isotope analyses and demographic responses counter prospects of planktivory by<Emphasis Type="Italic"> Caridina</Emphasis> (Decapoda: Atyidae) in Lake Victoria

Caridina nilotica, a freshwater atyid prawn, is a vital component of the Lake Victoria ecosystem. Despite its important role in the food web leading to Nile perch, the diet of Caridina is not well understood. Caridina freshly collected from the inshore littoral and offshore plankton of Lake Victoria were cultured individually under laboratory conditions on (A) decomposing hydrophytes, (B) living hydrophytes, (C) planktonic algae, (D) zooplankton and (E) 35- microm filtered lake water (a 'starvation' control). Inter-moult intervals (IMI, days), size-standardized moult intervals (MI, days mm(-1)), per moult growth increments (PMI, mm) and survivorship (%) were monitored daily for up to 5 weeks. Significant effects of both food type and shrimp source on MI were revealed by ANOVA. MI increased progressively from treatment A to D, and was shorter in offshore than littoral shrimps. Food influence on IMI was confirmed by ANCOVA. PMI values were close to the limits of detection, but were generally in line with MI responses. PMI values were marginal in treatments A and B, and negligible or negative in treatments D and especially E. Survivorship values, although confounded by non-dietary factors, were generally consistent with dietary influences on MI, although values obtained for treatment E were inconsistently high for true starvation. Disparate responses between inshore and offshore shrimps hint at possible ecotypic differentiation, or perhaps the existence of cryptic species. Stable isotope analyses (SIA, delta13C and delta15N signatures) of cultured shrimps were further consistent with their utilization of food type A but not D. SIA signatures of feral shrimps maintained in situ in enclosure bags with three separate potential fresh hydrophyte food sources (Vossia cuspidata, Cyperus papyrus, and Eichhornia crassipes) reflected Caridina's probable dietary reliance on decomposed organic matter with accompanying bacterial exudates. Collections of feral shrimps from various locations yielded parallel SIA results. No support for zooplanktivory by shrimps occupying either inshore littoral/benthic or offshore planktonic habitats is provided by the delta15N signatures obtained from our data, which support Caridina's primary role as a detritivore.     

Genetic differentiation among populations of Caridinazebra (Decapoda: Atyidae) in tropical rainforest streams, northern Australia

1. Caridina zebra is a common atyid shrimp in some tropical rainforest streams in far north Queensland, Australia. Genetic variation at five allozyme loci was used to estimate the level of dispersal among populations of this species, within and between stream systems. Shrimps were sampled from nine streams in the Tully River catchment and two headwater streams in the adjacent Herbert River catchment in an area under consideration for extensive hydroelectric development.
2. High levels of genetic differentiation were recorded among most populations which suggests that, like other fully aquatic species, movement is limited to a very small spatial scale.
3. In the Tully catchment, populations of shrimp from streams with confluences at high altitude showed less genetic differentiation than those from streams which directly entered the lower river. Dispersal between the latter streams is clearly limited by the presence of large waterfalls and cascades.
4. Adjacent stream populations were often highly differentiated, despite their close proximity, suggesting that overland dispersal is unlikely. However, populations of shrimp in the two streams in the Herbert catchment were strikingly similar in genetic structure to those in adjacent headwater streams of the Tully. Such similarity may reflect relatively recent changes in drainage patterns.     

An island in the stream: Australia's place in the cosmopolitan world of Indo-West Pacific freshwater shrimp (Decapoda: Atyidae: Caridina)

Mitochondrial DNA sequences were used to investigate phylogenetic and biogeographic relationships among Australian freshwater shrimp from the genus Caridina H. Milne Edwards, 1837 (Atyidae) and congeners from potential source populations throughout the Indo-West Pacific region. Numerous Australian taxa have close evolutionary relationships with non-Australian taxa from locations throughout the region, indicating a diverse origin of the Australian freshwater fauna. This implies many colonisations to or from Australia over a long period, and thus highlights the surprising adeptness of freshwater shrimp in dispersal across ocean barriers and the unity of much of the region's freshwater biota. Interestingly, a study on Australia's other main genus of atyid shrimp, Paratya Miers, 1882, inferred only a single colonisation. A number of potential species radiations within Australia were also identified. This agrees with patterns detected for a large number of Australian freshwater taxa, and so implies a vicariant explanation due to the development of colder, dryer climates during the late Miocene/early Pliocene.     

Isolation and characterization of 15 microsatellite loci from Caridina gracilipes (Atyidae, Decapoda)

Caridina gracilipes, an atyid shrimp of Taiwan, inhabits the fresh and brackish waters. Its life history can be classified into amphidromous and landlocked types. Recent human’s transportation has caused concerns of genetic contamination between these long evolved lineages and ecological instabilities. Molecular markers with high sensitivities are required for detecting the possible introgression due to human disturbance. In the study, we described the development of 15 polymorphic microsatellite loci in C. gracilipes for genetic and ecological studies. These new markers were tested in 20 individuals of three populations. The number of alleles ranged from 6 to 17. Expected (H _E) and observed (H _O) heterozygosities ranged from 0.653 to 0.954, averaged at 0.865, and from 0.000 to 0.4, averaged at 0.146, respectively. All loci are significantly deviated from Hardy–Weinberg expectations due to the heterozygote deficiency. Significant genetic differentiation among populations was detected based on F _ST values, which were estimated from 0.82 to 0.88. Chiao-Chuan Han and Cheng-Sheng Chang are contributed equally to this work.     

Assessing the patterns and drivers of shape complexity in the amblypygid pedipalp

Amblypygi is an arachnid order possessing a unique pair of spined pedipalps: appendages that perform in prey capture, courtship, and contest. Pedipalp length, hypothesized to be under sexual selection, varies markedly across amblypygid species, and pedipalp spination, thought to reflect selection for function in prey capture, also differs interspecifically. Differences in pedipalp shape between species may indicate that the relative strength of selection for prey capture and sexual selection vary across the group. However, interspecific differences in pedipalp shape have not been quantified, due to difficulties in identifying homologous features. For the first time, we quantify trends in amblypygid pedipalp shape complexity. We use elliptical Fourier analysis to quantify 2D complexity in pedipalp outlines across eleven species and six genera. We find that complexity significantly decreases as pedipalp length increases. This appears to be driven by relative spine length, suggesting that a trade‐off exists between pedipalp length and spination. Furthermore, significant female‐biased sexual dimorphism in shape complexity is present in the tibial segment of the amblypygid pedipalp. Our results provide novel insights into the drivers of amblypygid pedipalp evolution and suggest that a functional trade‐off between performance in prey capture and other functions under sexual selection exist in this enigmatic structure.     

中国米虾bursicon基因的功能及作用机制

为探讨米虾鞣化激素在其蜕皮周期及表皮角质层形成过程中的作用, 采用PCR技术克隆得到了米虾鞣化激素两个亚基基因的开放阅读框(ORF)序列。bursicon-α ORF全长441 bp, 共编码146个氨基酸; bursicon-β ORF全长411 bp, 共编码136个氨基酸。利用实时荧光定量PCR分析米虾整个蜕皮周期中鞣化激素2个亚基基因的表达特征, 结果发现, 鞣化激素bursicon-α和bursicon-β在米虾蜕皮周期的各个阶段的相对表达量存在差异, 在蜕皮前期(D期)相对表达量开始上升, 到D₃期时相对表达量最高, 蜕皮期E期相对表达量最低。RNA干扰(RNA interference, RNAi)介导bursicon-α和bursicon-β基因沉默后, 发现米虾的蜕皮周期延长, 表皮角质层明显变薄。结果提示, 鞣化激素(Bursicon)与新形成的外骨骼中角质层的加厚与硬化密切相关, 进而影响蜕皮时间。     

Inter- and intraspecific differences in the life history and growth of Caridina spp. (Decapoda: Atyidae) in Hong Kong streams

1. The life‐history pattern of three populations of Caridina cantonensis (Atyidae) and one population of Caridina serrata were studied in four Hong Kong streams: Pak Ngau Shek (PNS), Kap Man Hang (KMH), Pak Tam Chung (PTC), and Lung Fu Shan (LFS). Caridina cantonensis occurred at PNS, KMH and PTC while C. serrata was present at LFS only. Monthly quantitative sampling was carried out at each study site over 2 years to investigate life‐history patterns and cohort‐specific growth rates. 2. Breeding by both species was mainly restricted to the wet season, and there was an increase in the incidence of ovigerous females as water temperatures rose at the start of the summer monsoon. The number of cohorts and the frequency of recruitment of C. cantonensis (one to three times each year) were highly site‐specific, but consistent between years. 3. Shrimp growth was size‐dependent, and decreased with increasing body size. Caridina cantonensis at PTC had the highest cohort‐specific growth rates (0.05–0.14 mg ash‐free dry weight (AFDW) mg^?1 day^?1), followed by C. serrata at LFS (6% lower), and C. cantonensis at KMH and PNS (16–39% lower). Shrimp life spans exceeded 1 year (17–22 months), depending on site and species. 4. Sexual maturity occurred at an earlier age and at a smaller size in populations with higher growth rates. Shrimps at PTC and LFS matured at approximately 4 months old; this was 3 months earlier than at KMH and 5 months earlier than at PNS. Females of C. cantonensis at PTC and C. serrata at LFS may have bred twice during each breeding season, while females in the other two populations bred once only. The number of cohorts produced by each population in each year did not vary between the years of the study. Most sexually mature individuals only survived long enough (for 10–12 months after maturation) to breed during one season. 5. The mean brood size of C. cantonensis varied among streams and was 25–28% larger at PNS and KMH than at PTC. Egg size did not differ among populations. Larger brood sizes at PNS and KMH may have been a consequence of increased availability of algal food in these unshaded stream sites. Caridina serrata had similar egg and brood sizes to C. cantonensis, but females were smaller and reproductive investment was higher. Thus, the degree of intraspecific variation in atyid breeding in Hong Kong was at least equal to, if not greater than, the extent of interspecific variation. Interspecific differences in life history may reflect the frequency of droughts and spate intensity experienced by C. serrata at LFS.     

shape Diploproctodaeum arothroni n. sp. (Digenea: Lepocreadiidae) from the pufferfish shape Arothron hispidus (L.) (Tetraodontidae) from Suva,Fiji, with a revised key to the species of the genus

The new species Diploproctodaeum arothroni (Lepocreadiidae: Diploproctodaeinae) is described from the tetraodontid fish Arothron hispidus from Fiji. It differs from its closest relatives, D. hakofugu, D. oviforme and D. momoaafata, in having 42–54 ovarian lobes, a vitellarium reaching to the pharynx and tegumental spination reaching almost to the posterior extremity. A revised key to the 17 recognised species of Diploproctodaeum is given.     

福建米虾新种和亚种的记述

根据教学需要,结合调查福建淡水虾的资源,在整理采到的标本中,发现米虾(Cari-dina)属中有一新种和二新亚种,叙述如下:厦门米虾Caridina amoyensis,sp.nov.观察过标本共182尾,体长13—21毫米,标本号数75-72-1(?);75-72-2♀,采于1975年10月11日。体型小。       

Status of Corynosoma (Acanthocephala: Polymorphidae) based on anatomical, ecological, and phylogenetic evidence, with the erection of Pseudocorynosoma n. gen

The possession of genital spines has been considered as a key taxonomic trait to differentiate Corynosoma from other genera of the Polymorphidae. However, Corynosoma currently consists of 2 groups of species with clear ecological and morphological divergences: the "marine" group (with ca. 30 species) infects mammals and piscivorous birds in the marine realm, whereas the "freshwater" group (with ca. 7 species) infects waterfowl in continental waters. Species from these groups differ in shape of body and neck, trunk spination, lemnisci length and shape, testes arrangement, and number and shape of cement glands. We tested whether species from these 2 groups formed a monophyletic assemblage based on a phylogenetic analysis by using 15 morphological characters. We also included species of Andracantha, Polymorphus, and Hexaglandula with which potential taxonomic conflicts could most likely arise. We obtained 108 equally most parsimonious trees of 32 steps, with a consistency index (CI) = 0.59, and a retention index (RI) = 0.82. The strict consensus tree indicated that the "freshwater" species of Corynosoma form a monophyletic assemblage closely related to some species of Polymorphus, whereas the "marine" species of Corynosoma are grouped together with Andracantha. Accordingly, Corynosoma is not a monophyletic assemblage, and Pseudocorynosoma n. gen. is proposed for the "freshwater" species of Corynosoma. This decision was strongly supported by (1) a functional comparison of foretrunk muscles between species of Polymophus, Andracantha, and Corynosoma; (2) a multivariate morphometric study of proboscis characters and egg size; and (3) an analysis of ecological patterns of host-parasite relationships.     

Atyid shrimps (Decapoda: Atyidae) influence the spatial heterogeneity of algal communities over different scales in tropical montane streams, Puerto Rico

1. Atyid (Decapoda: Atyidae) shrimps influence the distribution of algal communities over different scales in tropical montane streams of Puerto Rico. Within pools of an atyid-dominated stream, atyid shrimps enhanced patchiness in algal communities along the depth gradient. Algal bands occurred in shallow pool margins where atyids did not forage (< 3 cm below water surface), with significantly greater standing crop, taxon richness, and structural complexity than deeper areas. In deeper water, atyids reduced small-scale patchiness in algal community composition and maintained a low-growing understorey turf dominated by sessile diatoms (Bacillariophyta) and, sometimes, closely cropped, filamentous blue-greens (Cyanophyta).
2. Among pools of the atyid-dominated stream, atyids interacted with light to determine algal patchiness between stream margins and deeper areas. In sunny pools, algal standing crop was 140-fold greater in pool margins than in deeper areas where atyids foraged. In shaded pools, however, standing crop in pool margins was only 5-fold greater than in deeper areas. Effects of light on algal standing crop were greater outside atyid foraging areas than within, indicating that shrimp grazing overrides the positive effects of light.
3. In contrast to the atyid-dominated stream, algal communities in an atyid-poor stream were characterized by a high biomass of loosely attached epipelic diatoms and no depth zonation. Interstream rock and shrimp transplant experiments indicated that atyids significantly reduced algal standing crop and altered community composition on rocks from atyid-poor streams within 24 h. Results support the hypothesis that atyid shrimps play a major role in determining observed interstream differences in algal communities.     

On the First Phyllosoma Stage of Parribacus caledonicus Holthuis, 1960, Scyllarides squammosus (H. Milne-Edwards, 1837) and Arctides regalis Holthuis, 1963 (Crustacea, Decapoda, Scyllaridae) from New Caledonia

The first stage phyllosoma of Parribacus caledonicus, Scyllaridessquammosus and Arctides regalis hatched in aquaria from berriedfemales are described and illustrated. The three phyllosomataare very similar but they can be distinguished by three characters:total length, ratio of total length to third pereiopod lengthand the setation and spination on the second maxilla. A summaryis provided of those morphological characters of the first phyllosomataattributed to these genera in the literature.     

Atyid shrimps (Decapoda: Atyidae) influence the spatial heterogeneity of algal communities over different scales in tropical montane streams, Puerto Rico

1. Atyid (Decapoda: Atyidae) shrimps influence the distribution of algal communities over different scales in tropical montane streams of Puerto Rico. Within pools of an atyid-dominated stream, atyid shrimps enhanced patchiness in algal communities along the depth gradient. Algal bands occurred in shallow pool margins where atyids did not forage (< 3 cm below water surface), with significantly greater standing crop, taxon richness, and structural complexity than deeper areas. In deeper water, atyids reduced small-scale patchiness in algal community composition and maintained a low-growing understorey turf dominated by sessile diatoms (Bacillariophyta) and, sometimes, closely cropped, filamentous blue-greens (Cyanophyta).
2. Among pools of the atyid-dominated stream, atyids interacted with light to determine algal patchiness between stream margins and deeper areas. In sunny pools, algal standing crop was 140-fold greater in pool margins than in deeper areas where atyids foraged. In shaded pools, however, standing crop in pool margins was only 5-fold greater than in deeper areas. Effects of light on algal standing crop were greater outside atyid foraging areas than within, indicating that shrimp grazing overrides the positive effects of light.
3. In contrast to the atyid-dominated stream, algal communities in an atyid-poor stream were characterized by a high biomass of loosely attached epipelic diatoms and no depth zonation. Interstream rock and shrimp transplant experiments indicated that atyids significantly reduced algal standing crop and altered community composition on rocks from atyid-poor streams within 24 h. Results support the hypothesis that atyid shrimps play a major role in determining observed interstream differences in algal communities.