Review of crayfish color patterns in the Family Cambaridae (Astacoidea), with discussion of their possible importance

Zootaxa ◽  
2020 ◽  
Vol 4755 (1) ◽  
pp. 63-98
Author(s):  
GUENTER A. SCHUSTER
Keyword(s):  
Color Vision ◽  
Color Patterns ◽  
Low Light ◽  
Uv Sensitivity ◽  
Body Regions ◽  
The Family ◽  
Color Sensitivity ◽  
Distinct Color ◽  
Species Descriptions ◽  
Crayfish Species

The use of color photographs in crayfish species descriptions, state faunal books and popular articles is relatively recent. Except for verbal color descriptions, color and color patterns have not often been explored by crayfish researchers. Carotenoids and carotenoproteins are responsible for much of the color found in the integument and exoskeleton of crayfishes and other crustaceans. Research has shown variation in color may be the result of the environment, diet, molt stage and age, genetics, or a combination of these. Crayfishes possess color vision, may use polarization vision, and have the possibility of fluorescent vision. They also have very good low light vision. Crayfishes have a multichromatic range in color sensitivity; it ranges from blue to red, with no UV sensitivity. Color vision may be an important factor in intraspecific and interspecific competition, territoriality, camouflage, sexual selection, and communication. A distinction is made between base or background colors displayed in crayfishes and their exhibited color patterns. While actual base or background colors may vary among individual crayfishes, a case is made that color patterns show much less intraspecific variation. Distinct color patterns are the result of highly contrasting colors on appendages or parts of appendages such as chelae, leg joints, tail fan, spines, and tubercles. Body regions like the carapace and abdomen may also have contrasting spots, bands or stripes. Color patterns may be useful in better understanding crayfish taxonomy, phylogeny, and evolutionary convergence, and examples are provided. 

Anacroneuria spp. (Insecta: Plecoptera: Perlidae) as paratenic hosts of Pheromermis sp. (Nematoda: Mermithidae) in Venezuela

Nematology ◽  
2012 ◽  
Vol 14 (2) ◽  
pp. 185-190 ◽  
Author(s):  
Maribet Gamboa ◽  
Maria Mercedes Castillo ◽  
Ricardo Guerrero
Keyword(s):  
Body Size ◽  
Body Regions ◽  
Individual Host ◽  
The Family ◽  
Paratenic Hosts

Nematodes of the family Mermithidae are known as endoparasites of freshwater arthropods. Juveniles of Pheromermis sp. (Mermithidae) were found coiled inside stonefly nymphs collected at seven sites in the Guare and Emilia rivers in northern Venezuela. Prevalence in Anacroneuria blanca was 93.2% () and in A. caraca was 91.5% (). In A. blanca, a higher number of juveniles per individual host was observed than in A. caraca, a fact that is probably related to body size. Although parasites were observed in all body regions, the highest incidence occurred in the legs and thorax. Considering the nematode prevalence and intensity of parasitism, we consider individuals of Anacroneuria spp. to be important hosts of Pheromermis in these rivers.

scholarly journals Review on the molecular study of the Diplozoidae: analyses of currently available genetic data, what it tells us, and where to go from here

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Quinton Marco Dos Santos ◽  
Annemariè Avenant-Oldewage
Keyword(s):  
Sequence Data ◽  
Molecular Study ◽  
Turn Of The Century ◽  
Phylogenetic Study ◽  
Online Databases ◽  
Crucial Component ◽  
The Family ◽  
Molecular Information ◽  
Taxonomic Approach ◽  
Species Descriptions

Abstract The use of molecular tools in the study of parasite taxonomy and systematics have become a substantial and crucial component of parasitology. Having genetic characterisation at the disposal of researchers has produced mostly useful, and arguably more objective conclusions. However, there are several groups for which limited genetic information is available and, coupled with the lack of standardised protocols, renders molecular study of these groups challenging. The Diplozoidae are fascinating and unique monogeneans parasitizing mainly freshwater cyprinid fishes in Europe, Asia and Africa. This group was studied from a molecular aspect since the turn of the century and as such, limitations and variability concerning the use of these techniques have not been clearly defined. In this review, all literature and molecular information, primarily from online databases such as GenBank, were compiled and scrupulously analysed for the Diplozoidae. This was done to review the information, detect possible pitfalls, and provide a “checkpoint” for future molecular studies of the family. Hindrances detected are the availability of sequence data for only a limited number of species, frequently limited to a single sequence per species, and the heavy reliance on one non-coding ribosomal marker (ITS2 rDNA) which is difficult to align objectively and displays massive divergences between taxa. Challenging species identification and limited understanding of diplozoid species diversity and plasticity are also likely restricting factors, all of which hamper the accurate taxonomic and phylogenetic study of this group. Thus, a more integrated taxonomic approach through the inclusion of additional markers, application of more rigorous morphological assessment, more structured barcoding techniques, alongside thorough capturing of species descriptions including genetypes, genophore vouchers and reference collections in open sources are encouraged. The pitfalls highlighted are not singular to the Diplozoidae, and the study of other groups may benefit from the points raised here as well.

scholarly journals Diverse Cell Types, Circuits, and Mechanisms for Color Vision in the Vertebrate Retina

2019 ◽  
Vol 99 (3) ◽  
pp. 1527-1573 ◽  
Author(s):  
Wallace B. Thoreson ◽  
Dennis M. Dacey
Keyword(s):  
Color Vision ◽  
Ganglion Cells ◽  
Color Perception ◽  
Visible Spectrum ◽  
Cell Types ◽  
Photon Flux ◽  
Low Light ◽  
Vertebrate Retina ◽  
Light Levels ◽  
Synaptic Interactions

Synaptic interactions to extract information about wavelength, and thus color, begin in the vertebrate retina with three classes of light-sensitive cells: rod photoreceptors at low light levels, multiple types of cone photoreceptors that vary in spectral sensitivity, and intrinsically photosensitive ganglion cells that contain the photopigment melanopsin. When isolated from its neighbors, a photoreceptor confounds photon flux with wavelength and so by itself provides no information about color. The retina has evolved elaborate color opponent circuitry for extracting wavelength information by comparing the activities of different photoreceptor types broadly tuned to different parts of the visible spectrum. We review studies concerning the circuit mechanisms mediating opponent interactions in a range of species, from tetrachromatic fish with diverse color opponent cell types to common dichromatic mammals where cone opponency is restricted to a subset of specialized circuits. Distinct among mammals, primates have reinvented trichromatic color vision using novel strategies to incorporate evolution of an additional photopigment gene into the foveal structure and circuitry that supports high-resolution vision. Color vision is absent at scotopic light levels when only rods are active, but rods interact with cone signals to influence color perception at mesopic light levels. Recent evidence suggests melanopsin-mediated signals, which have been identified as a substrate for setting circadian rhythms, may also influence color perception. We consider circuits that may mediate these interactions. While cone opponency is a relatively simple neural computation, it has been implemented in vertebrates by diverse neural mechanisms that are not yet fully understood.

scholarly journals The family Histriobdellidae (Annelida, Polychaeta) including descriptions of two new species from Brazil and a new genus

1999 ◽  
Vol 68 (2) ◽  
pp. 95-108 ◽  
Author(s):  
Tatiana Menchini Steiner ◽  
A. Cecilia Z. Amaral
Keyword(s):  
New Species ◽  
Geographical Distribution ◽  
New Genus ◽  
The Family ◽  
Two New Species ◽  
Species Descriptions

We review the family Histriobdellidae and provide species descriptions and notes on geographical distribution based on data from the literature. The morphological structures used in the systematics of this family are defined. A new genus, Dayus, is proposed and two new species from Brazil, Stratiodrilus robustus and S. circensis, are described.

scholarly journals The color of night: Surface color categorization by color defective observers under dim illuminations

2008 ◽  
Vol 25 (3) ◽  
pp. 475-480 ◽  
Author(s):  
JOEL POKORNY ◽  
MARGARET LUTZE ◽  
DINGCAI CAO ◽  
ANDREW J. ZELE
Keyword(s):  
Color Vision ◽  
Surface Color ◽  
Low Light ◽  
Light Levels ◽  
Color Categories ◽  
Wide Range ◽  
Basic Color ◽  
Color Vision Deficiencies ◽  
Orange Color ◽  
Color Scales

People with normal trichromatic color vision experience variegated hue percepts under dim illuminations where only rod photoreceptors mediate vision. Here, hue perceptions were determined for persons with congenital color vision deficiencies over a wide range of light levels, including very low light levels where rods alone mediate vision. Deuteranomalous trichromats, deuteranopes and protanopes served as observers. The appearances of 24 paper color samples from the OSA Uniform Color Scales were gauged under successively dimmer illuminations from 10 to 0.0003 Lux (1.0 to −3.5 log Lux). Triads of samples were chosen representing each of eight basic color categories; “red,” “pink,” “orange,” “yellow,” “green,” “blue,” “purple,” and “gray.” Samples within each triad varied in lightness. Observers sorted samples into groups that they could categorize with specific color names. Above −0.5 log Lux, the dichromatic and anomalous trichromatic observers sorted the samples into the original representative color groups, with some exceptions. At light levels where rods alone mediate vision, the color names assigned by the deuteranomalous trichromats were similar to the color names used by color normals; higher scotopic reflectance samples were classified as blue-green-grey and lower reflectance samples as red-orange. Color names reported by the dichromats at the dimmest light levels had extensive overlap in their sample scotopic lightness distributions. Dichromats did not assign scotopic color names based on the sample scotopic lightness, as did deuteranomalous trichromats and colour-normals. We reasoned that the reduction in color gamut that a dichromat experiences at photopic light levels leads to a limited association of rod color perception with objects differing in scotopic reflectance.

Chromosomal analysis of three Brazilian "eleutherodactyline" frogs (Anura: Terrarana), with suggestion of a new species

Zootaxa ◽  
2008 ◽  
Vol 1860 (1) ◽  
pp. 51 ◽  
Author(s):  
SÉRGIO SIQUEIRA ◽  
ODAIR AGUIAR JR. ◽  
CHRISTINE STRÜSSMANN ◽  
MARIA LÚCIA DEL-GRANDE ◽  
SHIRLEI MARIA RECCO-PIMENTEL
Keyword(s):  
New Species ◽  
Chromosome Number ◽  
Morphological Characteristics ◽  
Sampling Location ◽  
Color Patterns ◽  
Ecological Data ◽  
Mato Grosso ◽  
Distinct Color ◽  
Systematic Relationships ◽  
A New Species

The karyotypes of four Brazilian “eleutherodactyline” samples were analyzed aiming to provide additional cytogenetic data for future understanding of the evolutionary and systematic relationships of this large anuran group. The populations consisted of Pristimantis dundeei (Chapada dos Guimarães and Rondonópolis, Mato Grosso), Pristimantis aff. dundeei (Aripuanã, Mato Grosso) and Ischnocnema paulodutrai (Ilhéus, Bahia). The data revealed that P. dundeei and P. aff. dundeei have 2n=28 chromosomes, whereas I. paulodutrai has 2n=30. All pairs of chromosomes were telocentric, except for the subtelocentric pair 4 in I. paulodutrai. Differences in Ag-NOR pattern and interstitial heterochromatin positions clearly distinguished P. aff. dundeei from P. dundeei, and differentiated them from I. paulodutrai. The specimens of I. paulodutrai showed two distinct color patterns, but they did not differ in their cytogenetic characteristics. Karyotypes with 2n=28 and 2n=30 chromosomes have not been previously described for Brazilian “eleutherodactylines” which, to date, had been characterized as 2n=20, 2n=22 and 2n=34. The NOR position differences identified between P. dundeei and P. aff. dundeei, allied to their known distinct behavior and ecological data, suggested that the P. aff. dundeei from the Aripuanã sampling location is a new species. Similarities between I. paulodutrai and species currently assigned to Pristimantis are herein discussed on the basis of chromosome number and morphological characteristics.

scholarly journals Spatial summation improves bird color vision in low light intensities

2017 ◽  
Vol 130 ◽  
pp. 1-8 ◽  
Author(s):  
Peter Olsson ◽  
David Wilby ◽  
Almut Kelber
Keyword(s):  
Color Vision ◽  
Spatial Summation ◽  
Low Light ◽  
Light Intensities

scholarly journals Prediction of whole-genome DNA–DNA similarity, determination of G+C content and phylogenetic analysis within the family Pasteurellaceae by multilocus sequence analysis (MLSA)

Microbiology ◽  
2006 ◽  
Vol 152 (9) ◽  
pp. 2537-2548 ◽  
Author(s):  
Peter Kuhnert ◽  
Bożena M. Korczak
Keyword(s):  
Dna Hybridization ◽  
Gold Standard ◽  
Classical Method ◽  
Gene Sequencing ◽  
Dna Relatedness ◽  
Experimental Variation ◽  
The Family ◽  
Taxonomic Studies ◽  
Species Descriptions

Genome predictions based on selected genes would be a very welcome approach for taxonomic studies, including DNA–DNA similarity, G+C content and representative phylogeny of bacteria. At present, DNA–DNA hybridizations are still considered the gold standard in species descriptions. However, this method is time-consuming and troublesome, and datasets can vary significantly between experiments as well as between laboratories. For the same reasons, full matrix hybridizations are rarely performed, weakening the significance of the results obtained. The authors established a universal sequencing approach for the three genes recN, rpoA and thdF for the Pasteurellaceae, and determined if the sequences could be used for predicting DNA–DNA relatedness within the family. The sequence-based similarity values calculated using a previously published formula proved most useful for species and genus separation, indicating that this method provides better resolution and no experimental variation compared to hybridization. By this method, cross-comparisons within the family over species and genus borders easily become possible. The three genes also serve as an indicator of the genome G+C content of a species. A mean divergence of around 1 % was observed from the classical method, which in itself has poor reproducibility. Finally, the three genes can be used alone or in combination with already-established 16S rRNA, rpoB and infB gene-sequencing strategies in a multisequence-based phylogeny for the family Pasteurellaceae. It is proposed to use the three sequences as a taxonomic tool, replacing DNA–DNA hybridization.

A new species of stygobiont freshwater planarian (Platyhelminthes, Tricladida) from a chemoautotrophic ecosystem: the Frasassi karst in Italy

Zootaxa ◽  
2017 ◽  
Vol 4323 (4) ◽  
pp. 547 ◽  
Author(s):  
GIACINTA ANGELA STOCCHINO ◽  
RONALD SLUYS ◽  
ALESSANDRO MONTANARI ◽  
RENATA MANCONI
Keyword(s):  
New Species ◽  
The Body ◽  
Freshwater Planarian ◽  
Body Regions ◽  
The Family ◽  
A New Species

In this paper we report a new species of Dendrocoelum from the chemoautotrophic ecosystem of the Frasassi hypogenic cave complex in the northeastern Apennines of Italy. Dendrocoelum leporii Stocchino & Sluys, sp. nov. is characterized by the presence of a muscular atrial valve, which is unique within the genus. Moreover, the new species is characterized also by a penis papilla with a pseudoflagellum, numerous testes situated in the ventral, dorsal and median body regions with the follicles extending to the far posterior end of the body, and a large adenodactyl with the so-called Balkan type of musculature. The new species represents the twelfth dendrocoelid species recorded for Italy. A summary is provided of the species of the family Dendrocoelidae Hallez, 1892 thus far reported for the mainland and the isles of Italy. 

scholarly journals "Defense" injuries in attacks on humans by domestic dog (Canis lupus familiaris) and jaguar (Panthera onca)

2019 ◽  
Vol 5 (2) ◽  
pp. 81-84
Author(s):  
Manoel Francisco de Campos Neto ◽  
Vidal Haddad Junior
Keyword(s):  
Soft Tissue ◽  
Canis Lupus ◽  
Wild Animal ◽  
Domestic Dog ◽  
Canis Lupus Familiaris ◽  
Panthera Onca ◽  
Mato Grosso ◽  
Body Regions ◽  
The Family ◽  
Midwest Region

This communication describes two attacks by domestic and wild carnivores in Caceres County, localized in the Pantanal area, an extensive flooded plain in Mato Grosso State, Midwest region of Brazil. The first attack took place in an urban area and was caused by a Rottweiler dog (Canis lupus familiaris) created by the family of the victim. Another attack occurred in a rural area, caused by a jaguar (Panthera onca), which was disturbed while feeding, characterizing an unprovoked attack. Both the patients were wounded in the forearm, with different severity of the wounds. The lesions restricted to the forearm were the consequence of the victims using their arms as a shield, featuring the "defense" injuries, but the severity of the wounds were proportional to the strength of the attacking carnivore. Health staffs and emergency centers should be alert for soft tissue and bone injuries in the observed body regions after domestic and wild animal attacks.

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