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1.
The goatfishes (Mullidae) include about 50 bottom-foraging fish species. The foraging activity of the yellow goatfish, Mulloidichthys martinicus, and the spotted goatfish, Pseudupeneus maculatus, was studied comparatively at Fernando de Noronha Archipelago, off coast of Northeast Brazil tropical West Atlantic. Pseudupeneus maculatus fed over a larger variety of substrate types, had lower feeding rate, roamed more per given time, spent less time in a feeding event, and displayed a more diverse repertoire of feeding modes than M. martinicus. The differences in the foraging activity and behaviour between the two species possibly minimize a potential resource overlap, as already recorded for other sympatric mullids. Pseudupeneus maculatus had lower feeding rate most likely because it feeds on larger items, and roamed over greater distance per time. Possibly this is because it foraged over a greater variety of substrate distributed over a larger area than that used by M. martinicus. Notwithstanding the overall morphological and behavioural similarity of goatfishes in general, they do differ in their substrate preferences and foraging activity, which indicates that these fishes should not be simply considered generalized bottom foragers.  相似文献   

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This study reports the results of 5 years of monitoring reef fish post-larvae using light traps in the Bay of Tamandaré, north-east Brazil. An annotated checklist of pre-settlement fish species, their frequency of occurrence and taxonomic characteristics are provided. In total, 4,422 post-larval fishes belonging to 36 families, 56 genera and 76 species were captured. The most species-rich families were Carangidae (7), Lutjanidae (6) and Pomacentridae (4), while the families Gerreidae (30.47%), Holocentridae (16.54%), Blenniidae (12.01%), Labrisomidae (8.36%), Lutjanidae (8.29%) and Acanthuridae (5.95%) were the most abundant. This is the first study of the taxonomic diversity and assemblage structure of settlement-stage reef fishes in the tropical south-west Atlantic Ocean. Although a few common species were not captured due to selectivity of light traps, the composition and taxonomic diversity of this first collection suggests that light traps are useful for studies of the early life history of a wide range of pre-settlement reef fishes.  相似文献   

5.
The karyotype of Amphisbaena ridleyi, an endemic species of the archipelago of Fernando de Noronha, in State of Pernambuco, Brazil, is described after conventional staining, Ag-NOR impregnation and fluorescence in situ hybridization (FISH) with a telomeric probe. The diploid number is 46, with nine pairs of macrochromosomes (three metacentrics, four subtelocentrics and two acrocentrics) and 14 pairs of microchromosomes. The Ag-NOR is located in the telomeric region of the long arm of metacentric chromosome 2 and FISH revealed signals only in the telomeric region of all chromosomes. Further cytogenetic data on other amphisbaenians as well as a robust phylogenetic hypothesis of this clade is needed in order to understand the evolutionary changes on amphisbaenian karyotypes.  相似文献   

6.
The main goal of the present study was to test if two sympatric species of Heliconia, Heliconia spathocircinata and Heliconia laneana var. flava, differ in their reproductive seasons and guilds of flower visitors. Twenty-four sampling sessions were conducted monthly between February 2001 and January 2003. Individuals of H. spathocircinata and of H. laneana var. flava were tagged within a transect of 4000×4 m. Reproductive phenophases (flowering, unripe, and ripe fruits) were recorded, and circular statistics were used to test for the regularity and frequency of phenophases. Flower visitors were observed during two flowering periods for each species. Both species had well-defined and synchronous reproductive periods, with a small overlap, suggesting a sequential flowering model. Biotic and abiotic factors seem to affect phenophases of both species. However, herbarium data suggest that the flowering period in H. spathocircinata varies less than in H. laneana, despite its wider geographic distribution. The hummingbird Phaethornis idaliae was the main floral visitor of both Heliconia species studied. H. laneana was also legitimately visited by another hummingbird species, Glaucis hirsuta, and by Lepidoptera. Some Lepidoptera, particularly the bee Trigona spinipes, were illegitimate visitors (‘nectar robbers’). We suggest that the flower of H. spathocircinata allowed a wider array of visitors, because it is bigger.  相似文献   

7.
Synopsis A recent (1979) expedition to the Chagos Archipelago resulted in the collection of about 40 new taxa of fishes. A new genus,Trimmatom, and two new species,T. nanus andT. offucius, are described here. The new genus is characterized by having all pelvic-fin rays simple (unbranched), a scaleless body, no head pores, a wide gill opening extending anteroventrally to below the eye, and hypurals 1 and 2 fused to the complex formed by the fusion of the ural centrum and hypurals 3 and 4.T. nanuss andT. offucius are differentiated on the basis of fin ray counts and colour pattern.T. nanus is the smallest vertebrate yet to be described. Mature females with ovaries full of eggs are 8–10 mm in standard length.  相似文献   

8.
Hybridization is recognized as an important source of genetic variation. In some reef fishes, including the Acanthuridae, hybridization has been detected due to intermediate colouration. This study used a molecular genetic approach to investigate hybridization in two Acanthurid species: Acanthurus leucosternon and Acanthurus nigricans, which have Indian and Pacific Ocean distributions respectively and are sympatric in the eastern Indian Ocean. In this area a putatitve hybrid, Acanthurus cf. leucosternon has been recognized based on intermediate colouration and restriction to the sympatric region of otherwise allopatric putative parental species. This study aimed to test this hypothesis using genetic tools. The three species were sampled from Cocos (Keeling) and Christmas Islands, the biogeographic boundary where many Indian and Pacific Ocean biota meet. Representatives from allopatric populations of both parental species and outgroups were also sampled. Mitochondrial COI and intron 1 of the nuclear ribosomal protein S7 were sequenced from 13 and 30 specimens respectively. Although sample sizes in this study are relatively small and more genetic data, including an extended phylogeographic sampling, is required to further evaluate these findings, the COI results support hybrid origins of Acanthurus cf. leucosternon, but S7 data are inconclusive due to the possibility of incomplete lineage sorting. The fourfold more abundant Acanthurus nigricans is most often the maternal parent. Inter-fertile hybrids apparently backcross with rare Acanthurus leucosternon males, transferring Acanthurus nigricans mitochondria to this species. These results suggest that Acanthurus leucosternon may eventually be lost from these islands, due to their relative rarity and introgressive hybridization.  相似文献   

9.
A new species of Leguminosae is described and illustrated:Martiodendron fluminense, the southernmost and the only species of the genus to occur in the Atlantic forests of southeastern Brazil.  相似文献   

10.
A new species of Vitaceae is described and illustrated:Cissus pinnatifolia, the eighth species of the genus with pinnately compound leaves; an emended key to this group of species is also presented.  相似文献   

11.
Summary The pineal complexes of two deep-sea fishes, Bathylagus wesethi (family Bathylagidae) and Nezumia liolepis (family Macrouridae), were studied with both light and electron microscopy. Receptor and supportive cells were identified in the pineals of both species. The presence of receptor cells suggests that the pineals function in photoreception. Ganglion cells could be identified only in B. wesethi. A dorsal sac and a paraphysis were found in B. wesethi; both structures are absent in N. liolepis.Several trends were found when the results of this study were compared with those of a study on the pineal complex of another deep-sea fish, the myctophid Triphoturus mexicanus (McNulty and Nafpaktitis, 1976). Two of these trends, which are correlated with the vertical distributions of the species studied, suggest an increase in the photosensitivity of the pineals. These are: 1) an increase in the average number of outer segment lamellar membranes per receptor cell, and 2) an increase in the ratio of receptor cells to nerve fibers in the pineal stalks.A functional relationship between the dorsal sac, paraphysis, and pineal central lumen was suggested. The relationship may involve secretory activities.  相似文献   

12.
Inga unica Barneby & J. W. Grimes, notable for a syndrome of: a) softly pilose foliage, b) emarginate leafstalks lacking nectaries, c) leaflets 2–3 pairs, of moderate size, d) filiform pliant peduncles, e) globose capitula, f) elongate linear floral bracts persistent after fall of the flowers, g) calyx more than half as long as corolla, and h) thin-textured fruit shattering after falling, is described, figured, and discussed. It appears related toI. (Leptinga) nutans (Vellozo) Martius ex Bentham.  相似文献   

13.
Quesnelia koltesii and Q. clavata, two new species of Bromeliaceae, are described and illustrated, and their affinities with related taxa are discussed. Both species are endemic to southern Bahia, occur in low population densities above 600 m elevation, and must be considered to be endangered.  相似文献   

14.
This study describes the application of a protocol for biological assessment of water quality at first to third order streams at Serra dos órg?os, an area covered by Atlantic Forest in Rio de Janeiro State, Brazil. Major impacts in the region are domestic effluents and deforestation. Our main objective is to establish biocriteria for the establishment of the Serra dos órg?os Multimetric Index (SOMI) based on benthic macroinvertebrates. We used data from previous studies, sampled by experienced biologists, from 1999 through 2002. The benthic macroinvertebrate community was sampled in 12 reference sites and seven impaired sites in three river basins: Guapimirim, Macaé and Grande, all from the same bioregion. From the 22 tested metrics, 6 were included in the SOMI (% Diptera, % Coleoptera, Family Taxa, EPT Taxa, BMWP-CETEC and % Shredders). Scores (5, 3 or 1) were developed for these metrics to allow for aggregation into the index. Seven intermediately impaired sites were used for evaluating the applicability of the multimetric index. We concluded that the SOMI is a robust easy-to-apply tool for biomonitoring programs in the Serra dos órg?os region, south-east Brazil. Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorised users. Handling editor: D. Dudgeon  相似文献   

15.
The pumping activity of the bivalve Mytulus edulus, Hiatella arctica, and solitary ascidian Styela rustica from the White Sea has been studied. The dependence of the pumping activity on the mass and size of animals has been analyzed. It was shown that the mussel is the most active filter-feeder, that the least value of the pumping activity has been registered for H. arctica, and that S. rustica occupies an intermediate position according this index. The results obtained are examined in connection with the competitive relationship of the animals in the fouling community.  相似文献   

16.
The electrical activity of single olfactory receptor neurons in male soybean looper (SBL) Pseudoplusia includens(Walker) and cabbage looper (CL) Trihoplusia ni(Hübner) moths was evaluated in response to stimulation with fixed amounts of the individual components of their respective pheromone blends. In common with earlier observations in the CL, there are at least two classes of morphologically distinct pheromone sensitive sensilla on the antenna of male SBL, each of which contains two olfactory receptor neurons. In both species, one class of sensilla contains an olfactory receptor neuron sensitive to (Z)-7-dodecen-1-ol acetate (Z-7, 12:AC), the major component in each insect's blend, and a companion receptor neuron which is sensitive to (Z)-7-dodecen-1-ol (Z7,12: OH). In both species the second class of sensilla contains an olfactory receptor neuron which is sensitive to one of the minor components of the pheromone blend. (Z)-5-dodecen-1-ol acetate (Z-5,12:AC) is an effective stimulus in SBL, whereas (Z)-7-tetradecen-1-ol acetate (Z-7,14:AC) is an effective stimulus in CL. However, these two stimulatory compounds have been identified only in the female CL gland; neither has been found in the SBL gland. Thus, in contrast to the CL, which has receptor neurons which are responsive exclusively to conspecific pheromone components, the SBL has a class of receptor neurons which is responsive to a minor component of another species' pheromone blend. Field-trapping assays in which Z-5,12:AC is added to the SBL blend suggest that this single CL component is a powerful inhibitor of male SBL behavioral responses to conspecific pheromone blends. The difference observed in the specificity of the receptor neurons in this second class of sensilla are thus believed to play an integral role in the isolation processes that are maintained between these two species and may well account for the observed behavioral differences in their responses to heterospecific pheromone blends.  相似文献   

17.
热带大西洋黄鳍金枪鱼垂直分布空间分析   总被引:2,自引:0,他引:2  
为了解热带大西洋黄鳍金枪鱼(Thunnus albacares)延绳钓适宜渔获水温的等温线时空分布,分析黄鳍适宜的垂直和水平空间分布范围,采用Argo浮标剖面温度数据重构热带大西洋13℃和距海洋表层水温8℃(Δ8℃)的月平均等温线场,网格化计算了13℃和Δ8℃等温线深度值和温跃层下界深度差,并结合大西洋金枪鱼会委员(International Commission for the Conservation of Atlantic Tunas ICCAT)的黄鳍金枪鱼延绳钓渔业数据,绘制了13℃和Δ8℃等温线深度与月平均CPUE的空间叠加图,用于分析热带大西洋黄鳍金枪鱼中心渔场单位捕捞努力渔获量(Catch per unit effort CPUE)时空分布和次表层环境季节性变化关系。结果表明,13℃等温线,在高值CPUE出现的海域深度值大多小于250 m,主要在170—249 m,深度值超过250 m的海域CPUE普遍较小。5°S—9°N区域,Δ8℃等温线高值CPUE出现的海域深度值大多小于150 m,主要在50—139 m;7—10月份在南半球的非洲西海岸,在Δ8℃等温线深度值为150—350 m的海域也会出现中心渔场。全年在低纬度区域,高渔获率的垂直分布深度更加集中。13℃等温线影响热带大西洋黄鳍金枪鱼的空间分布,温跃层下界温度影响黄鳍金枪鱼的垂直分布。采用频次分析和经验累积分布函数计算其适宜次表层环境因子分布,13℃等温线180—240 m;Δ8℃等温线50—139 m;与下界深度差:13℃等温线-70—29 m;海表以下8℃等温线30—149 m。文章初步得出热带大西洋黄鳍金枪鱼适宜的水平、垂直深度分布区间。结果可以辅助渔情预报,为热带大西洋黄鳍金枪鱼实际生产作业和资源管理提供参考依据。  相似文献   

18.
A comparison of branchial enzyme profiles indicates that the gills of Periophthalmodon schlosseri would have a greater capacity for energy metabolism through glycolysis than those of Boleophthalmus boddaerti. Indeed, after exposure to hypoxia, or anoxia, there were significant increases in the lactate content in the gills of P. schlosseri. In addition, exposure to hypoxia or anoxia significantly lowered the glycogen level in the gills of this mudskipper. It can be deduced from these results that the glycolytic flux was increased to compensate for the decrease in ATP production through anaerobic glycolysis. Different from P. schlosseri, although there was an increase in lactate production in the gills of B. boddaerti exposed to hypoxia, there was no significant change in the branchial glycogen content, indicating that a reversed Pasteur effect might have occurred under such conditions. In contrast, anoxia induced an accumulation of lactate and a decrease in glycogen in the gills of B. boddaerti. Although lactate production in the gills of these mudskippers during hypoxia was inhibited by iodoacetate, the decreases in branchial glycogen contents could not account for the amounts of lactate formed. The branchial fructose-2,6-bisphosphate contents of these mudskippers exposed to hypoxia or anoxia decreased significantly, leaving phosphofructokinase and glycolytic rate responsive to cellular energy requirements under such conditions. The differences in response in the gills of B. boddaerti and P. schlosseri to hypoxia were possibly related to the distribution of phosphofructokinase between the free and bound states.Abbreviations ADP adenosine diphosphate - ALD aldolase - ALT alanine transaminase - AST aspartate transaminase - ATP adenosine triphosphate - CS citrate synthase - EDTA ethylenediaminetetra-acetic acid - EGTA ethylene glycol tetra-acetic acid - F6P fructose-6-phosphate - F-1,6-P2 fructose-1,6-bisphosphate - F-2,6-P2 fructose-2,6-bisphosphate - FBPase fructose-1,6-bisphosphatese - GAPDH glyceraldehyde-3-phosphate dehydrogenase - GDH glutamate dehydrogenase - -GDH -glycerophosphate dehydrogenase - GPase glycogen phosphorylase - HK hexokinase - HOAD 3-hydroxyacyl-CoA dehydrogenase - IDH isocitrate dehydrogenase - IOA iodoacetic acid - LDH lactate dehydrogenase - LO lactate oxidizing activity - MDH malate dehydrogenase - 3-PG 3-phosphoglyceric acid - PEP phosphoenolpyruvate - PEPCK phosphoenolpyruvate carboxykinase - PGI phosphoglucose isomerase - PGK phosphoglycerate kinase - PFK 6-phosphofructo-1-kinase - PIPES piperazine-N, N-bis-(2-ethanesulphonic acid) - PK pyruvate kinase - PMSF phenylmethylsulphonyl fluoride - PR pyrurate reducing activity - SE standard error - SW seawater - TPI triosephosphate isomerase  相似文献   

19.
Synopsis Analysis of variance on mean dimensions of samples of larval Anisakis simplex from Atlantic salmon (Salmo salar) and Atlantic herring (Clupea harengus harengus) indicated that highly significant morphometric differences existed. Subsequent analyses were simplified by using only the total body length of the larvae which was easily measured. Also the multiple range tests indicated that length showed the highest degree of heterogeneity. No difference (P > 0.2) was detected in the lengths of larvae from male and female salmon and most analyses suggested there was no change in length of the larvae with an increase in age of the host. There was, however, significant heterogeneity in the length of larvae in salmon which had spent more than one winter at sea and this heterogeneity was related in some way to the geographic localities in which the samples were taken. Possible reasons for these differences and the use of morphometric variants of Anisakis as a biological indicator are discussed.  相似文献   

20.
A revision of Brazilian Augusta and general comments on the systematics of this genus are presented. The complex taxonomic history of this taxon has caused confusion over its correct nomenclature. The peculiar geographic distribution of Augusta has stimulated field observations and analysis of the ecology of the Brazilian ecosystems where this taxon occurs, which are here presented. The five Brazilian species of Augusta described by Pohl are here treated as ecotypes of A. longifolia. This species has two distinct varieties: var. Longifolia, widespread throughout the Brazilian cerrado, and var. parvifolia, endemic to the Atlantic forest near Rio de Janeiro. Typification, list of representative specimens, and distribution map of A. longifolia are also included.  相似文献   

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