Rhythmic activity of inshore migration of tropical freshwater glass eels of the genus Anguilla

2020 ◽  
Vol 103 (11) ◽  
pp. 1295-1308
Author(s):  
Takaomi Arai ◽  
Hagi Yulia Sugeha ◽  
Daniel Limbong ◽  
Katsumi Tsukamoto
Keyword(s):  
Rhythmic Activity ◽  
Glass Eels ◽  
Tropical Freshwater ◽  
Inshore Migration

scholarly journals SPECIES COMPOSITION OF FRESHWATER EELS (Anguilla spp.) IN EIGHT RIVERS FLOWING TO PALABUHANRATU BAY, SUKABUMI, INDONESIA

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Agus Alim Hakim ◽  
M Mukhlis Kamal ◽  
Nurlisa A Butet ◽  
Ridwan Affandi
Keyword(s):  
Cluster Analysis ◽  
Discriminant Analysis ◽  
Species Composition ◽  
Dominant Species ◽  
Morphological Identification ◽  
Morphometric Data ◽  
Freshwater Eel ◽  
Glass Eels ◽  
Freshwater Eels ◽  
Tropical Freshwater

Freshwater eel (Anguilla spp.) is a catadromus fish that migrates from freshwater into seawater for spawning and return to freshwater during larvae stage to grow. The objective of this study was to determine species composition of tropical freshwater eels based on morphology collected from several rivers flowing in to the Palabuhan Ratu Bay. Young, adult, and glass eels were caught in August 2014 until Desember 2014. Glass eels were only caught in Cimandiri River. Freshwater eels were classified by ano-dorsal length (AD) divided by total length (TL), cluster analysis, and discriminant analysis based on morphometric data. The results showed different AD/TL of young and adult, i.e., 1.93±0.51 for A. bicolor bicolor, and 16.99±0.65 for A. marmorata, and three different AD/TL of glass eels i.e.,1.72±1.05 for A. bicolor bicolor6.60±1.79 for A. nebulosa nebulosa, and 15.07±1.04 for A. marmorata. Cluster analysis showed three groups of population  characters of young and adult eels i.e.  A. bicolor bicolor (2 groups) and A. marmorata (1 group). Discriminant analysis showed three groups of glass eels population i.e., A. bicolor bicolor, A. nebulosa nebulosa, and A. marmorata. Morphological identification showed that young and adult eels in Cibareno  and Citepus rivers had two species i.e., A. bicolor bicolor and A. marmorata. Glass eels from Cimandiri river had three species i.e., A. bicolorbicolor, A. nebulosanebulosa, and A. marmorata. A. bicolor bicolor was found in each rivers and as a dominant species in Palabuhan Ratu Bay.Keywords: A. bicolor bicolor, A. marmorata, A. nebulosa nebulosa, species composition

Rhythmic activity of migrating juvenile American eels Anguilla rostrata

1988 ◽  
Vol 68 (1) ◽  
pp. 81-91 ◽  
Author(s):  
Gail S. Wippelhauser ◽  
James D. McCleave
Keyword(s):  
River Estuary ◽  
Rhythmic Activity ◽  
Water Current ◽  
Anguilla Rostrata ◽  
Activity Rhythms ◽  
Tidal Water ◽  
Penobscot River ◽  
Tidal Stream ◽  
Glass Eels ◽  
Stream Transport

Glass eels of the American eel Anguilla rostrata (Lesueur) utilize selective tidal stream transport, a series of semidiurnal vertical migrations in phase with the tide, to migrate up the Penobscot River estuary, Maine, U.S.A., in the spring. Glass eels, freshly collected during their migration, exhibited rhythmic activity with circatidal periodicities when tested in groups in the presence of a water current under constant conditions in the laboratory. Freshly collected groups of eels which had already completed their migration through tidal water did not exhibit circatidal activity rhythms under the same conditions. The activity rhythms of groups of eels freshly caught in tidal water appeared to be entrained by a 12.5 h cycle of water current reversals, but not by a 10.0 h cycle of current reversals. In other entrainment experiments water collected on flood and ebb tides was alternately added to the experimental tanks every 5.0 h. Under these conditions groups of eels freshly caught in tidal water did not display any rhythmic activity. Only 2 of 100 glass eels, freshly collected from tidal and non-tidal water, which were tested individually in static tanks, exhibited rhythmic activity. The activity rhythms would allow an eel to time its vertical migrations in the estuary despite varying environmental conditions.

scholarly journals Inshore migration of tropical glass eels (Anguilla spp.) in Lambeso River, Aceh Jaya District, Aceh Province, Indonesia

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Zainal A. Muchlisin ◽  
Maulidin Maulidin ◽  
Abdullah A. Muhammadar ◽  
Dedi F. Putra
Keyword(s):  
Opposite Direction ◽  
Spring Tide ◽  
Migration Time ◽  
Sampling Location ◽  
Weekly Basis ◽  
Aceh Province ◽  
Glass Eels ◽  
Initial Survey ◽  
Inshore Migration

The objective of the present study was to evaluate the migration time of glass eels (Anguilla spp.)  in the estuary of  Lambeuso River, Aceh Jaya District, Indonesia. The survey was done in March and June 2015.  The sampling location was determined based on an initial survey during February 2015 by considering the river condition. Based on initial survey there are no glass eels were recorded during noon time, and therefore the sampling was focused at night. The sampling was done four times a month (weekly basis) for three months (12 times in total) using trap nets based on Hijri Calendar. The trap was settled up to opposite direction of tide (seaward) from 18.00 PM to 06.00 AM  and the catches glass eels were monitoring one-hour interval.  A total of 131 glass eels were sampled during the study, where the samples were only caught on first (new month) and fourth week (old month) base on Hijri Calender  during spring tide and  no glass eels were sampled during second and third weeks. It was concluded that the migration time of the glass eels (Anguilla spp.) in Lambeso Rivers is during the dark moon at the new and old month of Hijri Calendar

Inshore migration and otolith microstructure/microchemistry of anguillid glass eels recruited to Iceland

2008 ◽  
Vol 83 (3) ◽  
pp. 309-325 ◽  
Author(s):  
Mari Kuroki ◽  
Momoko Kawai ◽  
Bjarni Jónsson ◽  
Jun Aoyama ◽  
Michael J. Miller ◽  
...  
Keyword(s):  
Otolith Microstructure ◽  
Glass Eels ◽  
Inshore Migration

scholarly journals Commissural Interneurons in Rhythm Generation and Intersegmental Coupling in the Lamprey Spinal Cord

1999 ◽  
Vol 81 (5) ◽  
pp. 2037-2045 ◽  
Author(s):  
James T. Buchanan
Keyword(s):  
Spinal Cord ◽  
Amino Acid ◽  
Excitatory Amino Acid ◽  
Rhythmic Activity ◽  
Ventral Root ◽  
Rhythm Generation ◽  
Spinal Segment ◽  
Spinal Segments ◽  
Autocorrelation Method

Commissural interneurons in rhythm generation and intersegmental coupling in the lamprey spinal cord. To test the necessity of spinal commissural interneurons in the generation of the swim rhythm in lamprey, longitudinal midline cuts of the isolated spinal cord preparation were made. Fictive swimming was then induced by bath perfusion with an excitatory amino acid while recording ventral root activity. When the spinal cord preparation was cut completely along the midline into two lateral hemicords, the rhythmic activity of fictive swimming was lost, usually replaced with continuous ventral root spiking. The loss of the fictive swim rhythm was not due to nonspecific damage produced by the cut because rhythmic activity was present in split regions of spinal cord when the split region was still attached to intact cord. The quality of this persistent rhythmic activity, quantified with an autocorrelation method, declined with the distance of the split spinal segment from the remaining intact spinal cord. The deterioration of the rhythm was characterized by a lengthening of burst durations and a shortening of the interburst silent phases. This pattern of deterioration suggests a loss of rhythmic inhibitory inputs. The same pattern of rhythm deterioration was seen in preparations with the rostral end of the spinal cord cut compared with those with the caudal end cut. The results of this study indicate that commissural interneurons are necessary for the generation of the swimming rhythm in the lamprey spinal cord, and the characteristic loss of the silent interburst phases of the swimming rhythm is consistent with a loss of inhibitory commissural interneurons. The results also suggest that both descending and ascending commissural interneurons are important in the generation of the swimming rhythm. The swim rhythm that persists in the split cord while still attached to an intact portion of spinal cord is thus imposed by interneurons projecting from the intact region of cord into the split region. These projections are functionally short because rhythmic activity was lost within approximately five spinal segments from the intact region of spinal cord.

scholarly journals Detection of Ventricular Fibrillation Based on Ballistocardiography by Constructing an Effective Feature Set

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3524
Author(s):  
Rongru Wan ◽  
Yanqi Huang ◽  
Xiaomei Wu
Keyword(s):  
Ventricular Fibrillation ◽  
Cross Validation ◽  
Rhythmic Activity ◽  
Detection Algorithm ◽  
Motion Artifacts ◽  
Cardiac Monitoring ◽  
Mechanical Activity ◽  
Time Frequency ◽  
S Transform ◽  
Fatal Arrhythmia

Ventricular fibrillation (VF) is a type of fatal arrhythmia that can cause sudden death within minutes. The study of a VF detection algorithm has important clinical significance. This study aimed to develop an algorithm for the automatic detection of VF based on the acquisition of cardiac mechanical activity-related signals, namely ballistocardiography (BCG), by non-contact sensors. BCG signals, including VF, sinus rhythm, and motion artifacts, were collected through electric defibrillation experiments in pigs. Through autocorrelation and S transform, the time-frequency graph with obvious information of cardiac rhythmic activity was obtained, and a feature set of 13 elements was constructed for each 7 s segment after statistical analysis and hierarchical clustering. Then, the random forest classifier was used to classify VF and non-VF, and two paradigms of intra-patient and inter-patient were used to evaluate the performance. The results showed that the sensitivity and specificity were 0.965 and 0.958 under 10-fold cross-validation, and they were 0.947 and 0.946 under leave-one-subject-out cross-validation. In conclusion, the proposed algorithm combining feature extraction and machine learning can effectively detect VF in BCG, laying a foundation for the development of long-term self-cardiac monitoring at home and a VF real-time detection and alarm system.

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