scholarly journals A new millipede-parasitizing horsehair worm, Gordius chiashanus sp. nov., at medium altitudes in Taiwan (Nematomorpha, Gordiida)

ZooKeys ◽  
2020 ◽  
Vol 941 ◽  
pp. 25-48
Author(s):  
Ming-Chung Chiu ◽  
Chin-Gi Huang ◽  
Wen-Jer Wu ◽  
Zhao-Hui Lin ◽  
Hsuan-Wien Chen ◽  
...  
Keyword(s):  
Forest Canopy ◽  
Heavy Rain ◽  
Paratenic Host ◽  
Ventral Side ◽  
The Body ◽  
High Tolerance ◽  
Free Living ◽  
Terrestrial Environment ◽  
White Stripe ◽  
Inside Wall

Gordius chiashanussp. nov., a newly described horsehair worm that parasitizes the Spirobolus millipede, is one of the three described horsehair worm species in Taiwan. It is morphologically similar to G. helveticus Schmidt-Rhaesa, 2010 because of the progressively broadening distribution of bristles concentrated on the male tail lobes, but it is distinguishable from G. helveticus because of the stout bristles on the mid-body. In addition, a vertical white stripe on the anterior ventral side and areoles on the inside wall of the cloacal opening are rarely mentioned in other Gordius species. Free-living adults emerged and mated on wet soil under the forest canopy in the winter (late November to early February) at medium altitudes (1100–1700 m). Mucus-like structure covering on the body surface, which creates a rainbow-like reflection, might endow the worm with high tolerance to dehydration. Although Gordius chiashanussp. nov. seems to be more adaptive to the terrestrial environment than other horsehair worm species, cysts putatively identified as belonging to this hairworm species found in the aquatic paratenic host, Ephemera orientalis McLachlan, 1875, suggest the life cycle of Gordius chiashanussp. nov. could involve water and land. The free-living adults emerged from the definitive hosts might reproduce in the terrestrial environment or enter an aquatic habitat by moving or being washed away by heavy rain instead of manipulating the behavior of their terrestrial definitive hosts.

Moulting and mating in Lepeophtheirus pectoralis (Copepoda: Caligidae)

1990 ◽  
Vol 70 (2) ◽  
pp. 269-281 ◽  
Author(s):  
Morten Anstensrud
Keyword(s):  
Adult Female ◽  
Anterior Margin ◽  
Ventral Side ◽  
Dorsal Side ◽  
The Body ◽  
Agonistic Behaviour ◽  
Free Living ◽  
Genital Complex ◽  
Frontal Filament ◽  
Receptaculum Seminis

Prior to moulting, the preadult Lepeophtheirus pectoralis produces a temporary frontal filament which attaches the animal to the surface of the host during ecdysis. This filament is extruded from a frontal organ previously thought to have a chemoreceptory function. During ecdysis the exuvium splits at the anterior margin and is shed posteriorly by contractions of the body. After hardening of the exoskeleton the copepod detaches itself from the frontal filament and is free-living on the host during intermoult. Males in precopula position hold on to the dorsal side of the female, with the second antennae grasping the anterior end of the female's genital complex. During the ecdysis of the female, most males release their hold on the female, and are usually found close to her on the host. Copulation occurs between an adult male and an adult female with a hardened exoskeleton. In the copula position the male holds on to the female's genital complex with the second antennae, but now on the ventral side of the female. Two spermatophores are extruded and then transferred simultaneously to the female with the aid of the second pair of swimming legs. Tubes originating from the spermatophores connect them to the orifices of the receptaculum seminis. These tubes seem to grow out of the spermatophores after expulsion. After copulation, the male retains a precopula position before releasing the female. No agonistic behaviour has been observed between a precopulating/copulating male and additional males. However, during the ecdysis of the female, a new male may take over the female, but mating does not seem to be assortative for size in Lepeophtheirus pectoralis.

Invariance of Wearing Location of Omron-BI Pedometers: A Validation Study

2010 ◽  
Vol 7 (6) ◽  
pp. 706-717 ◽  
Author(s):  
Weimo Zhu ◽  
Miyoung Lee
Keyword(s):  
Validation Study ◽  
Absolute Error ◽  
Activity Monitor ◽  
Error Rates ◽  
Living Conditions ◽  
The Body ◽  
Validity And Reliability ◽  
Free Living ◽  
Climbing Stairs ◽  
Free Living Conditions

Background:The purpose of this study was to investigate the validity and reliability evidences of the Omron BI pedometer, which could count steps taken even when worn at different locations on the body.Methods:Forty (20 males and 20 females) adults were recruited to walk wearing 5 sets, 1 set at a time, of 10 BI pedometers during testing, 1 each at 10 different locations. For comparison, they also wore 2 Yamax Digi-Walker SW-200 pedometers and a Dynastream AMP 331 activity monitor. The subjects walked in 3 free-living conditions: a fat sidewalk, stairs, and mixed conditions.Results:Except for a slight decrease in accuracy in the pant pocket locations, Omron BI pedometers counted steps accurately across other locations when subjects walked on the fat sidewalk, and the performance was consistent across devices and trials. When the subjects climbed up stairs, however, the absolute error % of the pant pocket locations increased significantly (P < .05) and similar or higher error rates were found in the AMP 331 and SW-200s.Conclusions:The Omron BI pedometer can accurately count steps when worn at various locations on the body in free-living conditions except for front pant pocket locations, especially when climbing stairs.

EARLY STAGES OF FIDONIA NOTATARIA, Walk

1882 ◽  
Vol 14 (10) ◽  
pp. 199-200 ◽  
Author(s):  
L. W. Goodell
Keyword(s):  
Pinus Strobus ◽  
White Hair ◽  
The Body ◽  
White Stripe ◽  
Yellowish Green ◽  
Yellow Body ◽  
Bright Green ◽  
Deep Green ◽  
Pale Green ◽  
Dorsal Stripe

Eggs.—Oblong, covered with hexagonal depressions and bright green in color. Length 0.6 mil.; width 0.3 mil. Duration of egg stage 12 days.Young Larva.—Length 2 mil.; head twice as wide as the body, round and deep ochre yellow; body dull yellowish green with a faint paler stigmatal stripe.Mature Larva.—Body of uniform thickness, deep green with a narrow sub-dorsal and stigmatal white stripe, and a dorsal greenish-white hair line; dorsal space pale green; ventral space yellowish green. Head brownish green with a lateral white stripe which is a continuation of the sub-dorsal stripe of the body. Length at rest 25 to 26 mil.; when crawling, 26 to 27 mil. Food plant, Pinus strobus. Duration of larva stage, 35 to 40 days. Described from 57 specimens.

Taxonomic description and 3D modelling of a new species of myzostomid (Annelida, Myzostomida) associated with black corals from Madagascar

Zootaxa ◽  
2017 ◽  
Vol 4244 (2) ◽  
pp. 277 ◽  
Author(s):  
LUCAS TERRANA ◽  
IGOR EECKHAUT
Keyword(s):  
New Species ◽  
Phylogenetic Analyses ◽  
Three Dimensional ◽  
Close Relation ◽  
Ventral Side ◽  
Middle Part ◽  
The Body ◽  
Taxonomic Description ◽  
Black Corals ◽  
Organ Systems

Eenymeenymyzostoma nigrocorallium n. sp. is the first species of myzostomid worm associated with black corals to be described. Endoparasitic specimens of E. nigrocorallium were found associated with three species of antipatharians on the Great Reef of Toliara. Individuals inhabit the gastrovascular ducts of their hosts and evidence of infestation is, most of the time, not visible externally. Phylogenetic analyses based on 18S rDNA, 16S rDNA and COI data indicate a close relation to Eenymeenymyzostoma cirripedium, the only other species of the genus. The morphology of E. nigrocorallium is very unusual compared to that of the more conventional E. cirripedium. The new species has five pairs of extremely reduced parapodia located on the body margin and no introvert, cirri or lateral organs. Individuals are hermaphroditic, with the male and female gonads both being located dorsally in the trunk. It also has a highly developed parenchymo-muscular layer on the ventral side, and the digestive system lies in the middle part of the trunk. A three-dimensional digital model of this worm’s body plan has been constructed whereby the external morphology and in toto views of the observed organ systems (nervous, digestive and reproductive) can be viewed on-screen: http://doi.org/10.13140/RG.2.2.17911.21923. 

scholarly journals Can't tell the caterpillars from the trees: countershading enhances survival in a woodland

2008 ◽  
Vol 275 (1651) ◽  
pp. 2539-2545 ◽  
Author(s):  
Hannah M Rowland ◽  
Innes C Cuthill ◽  
Ian F Harvey ◽  
Michael P Speed ◽  
Graeme D Ruxton
Keyword(s):  
Visual Cues ◽  
Field Experiments ◽  
Three Dimensional ◽  
Shape From Shading ◽  
The Body ◽  
Colour Pattern ◽  
Free Living ◽  
Background Matching ◽  
Lepidopteran Larvae ◽  
Beech Tree

Perception of the body's outline and three-dimensional shape arises from visual cues such as shading, contour, perspective and texture. When a uniformly coloured prey animal is illuminated from above by sunlight, a shadow may be cast on the body, generating a brightness contrast between the dorsal and ventral surfaces. For animals such as caterpillars, which live among flat leaves, a difference in reflectance over the body surface may degrade the degree of background matching and provide cues to shape from shading. This may make otherwise cryptic prey more conspicuous to visually hunting predators. Cryptically coloured prey are expected to match their substrate in colour, pattern and texture (though disruptive patterning is an exception), but they may also abolish self-shadowing and therefore either reduce shape cues or maintain their degree of background matching through countershading: a gradation of pigment on the body of an animal so that the surface closest to illumination is darker. In this study, we report the results from a series of field experiments where artificial prey resembling lepidopteran larvae were presented on the upper surfaces of beech tree branches so that they could be viewed by free-living birds. We demonstrate that countershading is superior to uniform coloration in terms of reducing attack by free-living predators. This result persisted even when we fixed prey to the underside of branches, simulating the resting position of many tree-living caterpillars. Our experiments provide the first demonstration, in an ecologically valid visual context, that shadowing on bodies (such as lepidopteran larvae) provides cues that visually hunting predators use to detect potential prey species, and that countershading counterbalances shadowing to enhance cryptic protection.

Quebecius quebecensis (Whiteaves), a porolepiform crossopterygian (Pisces) from the Late Devonian of Quebec, Canada

1987 ◽  
Vol 24 (12) ◽  
pp. 2351-2361 ◽  
Author(s):  
Hans-Peter Schultze ◽  
Marius Arsenault
Keyword(s):  
Ventral Side ◽  
The Body ◽  
Late Devonian ◽  
Pectoral Fin ◽  
Pectoral Fins ◽  
Median Fins ◽  
Pelvic Fin

Quebecius quebecensis (Whiteaves 1889) is a porolepiform crossopterygian related to Glyptolepis. A large nariodal, a large tabular, a separate intertemporal, and a large fused nasosupraorbital are features of Quebecius that characterize it as a porolepiform. The small size of the operculum, median extrascapular larger than the lateral one, small lower squamosals, and deep maxilla are additional features separating Quebecius from Glyptolepis. As in Glyptolepis, the median fins are not lobed. The pectoral fin possesses a long fleshy lobe. The internal, ventral side of the broadly based pelvic fin suggests that the internal axis has shifted towards the body. Pectoral fins with a long fleshy lobe are a common feature of porolepiforms, but lobed bases in the pelvic and unpaired fins are a feature found in Holoptychius, and not in Glyptolepis and Quebecius. Quebecius quebecensis is conspecific with Quebecius williamsi Schultze 1973, mistakenly described as an onychodont crossopterygian.

scholarly journals Plastic, nutrition and pollution; relationships between ingested plastic and metal concentrations in the livers of two Pachyptila seabirds

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lauren Roman ◽  
Farzana Kastury ◽  
Sophie Petit ◽  
Rina Aleman ◽  
Chris Wilcox ◽  
...  
Keyword(s):  
Health Hazard ◽  
Dietary Exposure ◽  
The Body ◽  
Free Living ◽  
Seabird Species ◽  
Significant Relationships ◽  
Naturally Occurring ◽  
Plastic Metal ◽  
Liver Concentration ◽  
New Evidence

Abstract Naturally occurring metals and metalloids [metal(loid)s] are essential for the physiological functioning of wildlife; however, environmental contamination by metal(loid) and plastic pollutants is a health hazard. Metal(loid)s may interact with plastic in the environment and there is mixed evidence about whether plastic ingested by wildlife affects metal(loid) absorption/assimilation and concentration in the body. We examined ingested plastic and liver concentration of eleven metal(loid)s in two seabird species: fairy (Pachyptila turtur) and slender-billed prions (P. belcheri). We found significant relationships between ingested plastic and the concentrations of aluminium (Al), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu) and zinc (Zn) in the liver of prions. We investigated whether the pattern of significant relationships reflected plastic-metal(loid) associations predicted in the scientific literature, including by transfer of metals from ingested plastics or malnutrition due to dietary dilution by plastics in the gut. We found some support for both associations, suggesting that ingested plastic may be connected with dietary dilution / lack of essential nutrients, especially iron, and potential transfer of zinc. We did not find a relationship between plastic and non-essential metal(loid)s, including lead. The effect of plastic was minor compared to that of dietary exposure to metal(oid)s, and small plastic loads (< 3 items) had no discernible link with metal(loid)s. This new evidence shows a relationship between plastic ingestion and liver metal(loid) concentrations in free-living wildlife.

scholarly journals Smartphone Monitoring of Gait and Balance During Irregular Surface Walking and Obstacle Crossing

2020 ◽  
Vol 2 ◽  
Author(s):  
Janeesata Kuntapun ◽  
Patima Silsupadol ◽  
Teerawat Kamnardsiri ◽  
Vipul Lugade
Keyword(s):  
Older Adults ◽  
Intraclass Correlation ◽  
Step Length ◽  
Living Environment ◽  
The Body ◽  
Irregular Surface ◽  
Time Step ◽  
Free Living ◽  
Obstacle Crossing ◽  
Gait Adaptation

As gait adaptation is vital for successful locomotion, the development of field-based tools to quantify gait in challenging real-world environments are crucial. The aims of this study were to assess the reliability and validity of a smartphone-based gait and balance assessment while walking on unobstructed and obstructed terrains using two phone placements. Furthermore, age-related differences in smartphone-derived gait strategies when navigating different walking conditions and environments were evaluated. By providing a method for evaluating gait in the simulated free-living environment, results of this study can elucidate the strategies young and older adults utilize to navigate obstructed and unobstructed walking paths. A total of 24 young and older adults ambulated indoors and outdoors under three conditions: level walking, irregular surface walking, and obstacle crossing. Android smartphones placed on the body and in a bag computed spatiotemporal gait (i.e., velocity, step time, step length, and cadence) and balance (i.e., center of mass (COM) displacement), with motion capture and video used to validate parameters in the laboratory and free-living environments, respectively. Reliability was evaluated using the intraclass correlation coefficient and validity was evaluated using Pearson's correlation and Bland-Altman analysis. A three-way ANOVA was used to assess outcome measures across group, condition, and environment. Results showed that smartphones were reliable and valid for measuring gait across all conditions, phone placements, and environments (ICC2,1: 0.606–0.965; Pearson's r: 0.72–1.00). Although body and bag placement demonstrated similar results for spatiotemporal parameters, accurate vertical COM displacement could only be obtained from the body placement. Older adults demonstrated a longer step time and lower cadence only during obstacle crossing, when compared to young adults. Furthermore, environmental differences in walking strategy were observed only during irregular surface walking. In particular, participants utilized a faster gait speed and a longer step length in the free-living environment, compared to the laboratory environment. In conclusion, smartphones demonstrate the potential for remote patient monitoring and home health care. Along with being easy-to-use, inexpensive, and portable, smartphones can accurately evaluate gait during both unobstructed and obstructed walking, indoors and outdoors.

scholarly journals Terrestrial Locomotion in American Eels (Anguilla rostrata): How Substrate and Incline Affect Movement Patterns

2020 ◽  
Vol 60 (1) ◽  
pp. 180-189
Author(s):  
Erica Redmann ◽  
Alina Sheikh ◽  
Areej Alqahtani ◽  
Mica McCarty-Glenn ◽  
Shazrah Syed ◽  
...  
Keyword(s):  
Wave Amplitude ◽  
Body Position ◽  
The Body ◽  
Complex Life Cycle ◽  
Anguilla Rostrata ◽  
American Eel ◽  
Distance Ratio ◽  
Terrestrial Environment ◽  
Terrestrial Locomotion ◽  
American Eels

Synopsis Fishes overcome a variety of challenges in order to invade the terrestrial environment. Terrestrial invasions by fish occur over a variety of environmental contexts. In order to advance their bodies on land, fishes capable of terrestrial excursions tend to use one of three different types of locomotor modes: axial-based, appendage-based, or axial-appendage-based. Elongate species with reduced appendages, such as the American eel, Anguilla rostrata, rely on axial based locomotion in water and on land. When eels move from water to land as part of their complex life cycle, they inevitably encounter a variety of substrates and must traverse variable degrees of incline. The aim of this study was to determine the effect of substrate and incline on the terrestrial locomotion of the American eel. In order to do this, eels were filmed from a dorsal view on three substrates and four inclines: sand, loose pebbles, and fixed (glued) pebbles at 0°, 5°, 10°, and 15°. We digitized 20 evenly spaced points along the body to examine the following characteristics of locomotion: velocity, distance ratio (DR), and wave parameters such as wave amplitude, frequency, and length and assessed whether substrate, incline, or body position affected these parameters. DR, our metric of movement efficiency, was highest on the flat sand condition and lowest on 15° pebble conditions. Efficiency also varied across the body. Velocity followed a similar pattern being highest on sand at 0° and lowest at the steepest inclines. Wave amplitude generally increased toward the tail but was similar across substrates and inclines. Wave frequency was relatively consistent across the body on both pebble substrates, but on sand, frequency was higher toward the head but decreased toward the tail. Wavelengths on sand were the longest at 0° near the head and shorter wavelengths were observed on steeper inclines. Both pebble substrates elicited lower wavelengths that were more similar across the body. Overall, A. rostrata were more effective in navigating compliant substrates but struggled at steeper inclines. Our findings provide insight into locomotor challenges that American eels may encounter as they move from and between bodies of water.

Sign in / Sign up

Export Citation Format

Share Document