Morphometrics of the eyes and orbits of the nocturnal Swallow-tailed Gull (Creagrus furcatus)

2010 ◽  
Vol 88 (9) ◽  
pp. 855-865 ◽  
Author(s):  
Andrew N. Iwaniuk ◽  
Christopher P. Heesy ◽  
Margaret I. Hall
Keyword(s):  
Visual System ◽  
Detailed Analysis ◽  
Optical Axis ◽  
Feeding Habits ◽  
Size And Shape ◽  
Nocturnal Feeding ◽  
Significant Difference ◽  
Orbit Orientation ◽  
Unique Species

The Swallow-tailed Gull ( Creagrus furcatus (Neboux, 1846)) is known for its nocturnal feeding habits and apparently large eyes. Despite frequent observations of its large eyes, detailed measurements of its eyes and orbits are wanting. Here, we provide a detailed analysis of the size and shape of the eye and orbits of this unique species in relation to a range of other gull species. Although the C. furcatus does have a slightly enlarged cornea and optical axis, neither the transverse orbit diameter nor the shape of its eye differs significantly from other larids. In addition, we found no significant difference between C. furcatus and other gulls in terms of its orbit dimensions and orbit orientation. We therefore conclude that C. furcatus does not possess a transversely enlarged eye, but rather a slightly larger cornea and longer eye. Our results do not, however, preclude the presence of other changes in the visual system, such as retinal morphology or neurophysiology, that could be adaptive for nocturnal feeding.

Utilizing next-generation sequencing to identify prey DNA in western North Atlantic grey seal Halichoerus grypus diet

2020 ◽  
Vol 655 ◽  
pp. 227-240
Author(s):  
KR Flanders ◽  
ZH Olson ◽  
KA Ono
Keyword(s):  
Next Generation Sequencing ◽  
Feeding Habits ◽  
Atlantic Menhaden ◽  
Halichoerus Grypus ◽  
Frequency Of Occurrence ◽  
Grey Seal ◽  
Next Generation ◽  
Significant Difference ◽  
Generation Sequencing ◽  
Seal Diet

Increasing grey seal Halichoerus grypus abundance in coastal New England is leading to social, political, economic, and ecological controversies. Central to these issues is the foraging ecology and diet composition of the seals. We studied grey seal feeding habits through next-generation sequencing of prey DNA using 16S amplicons from seal scat (n = 74) collected from a breeding colony on Monomoy Island in Massachusetts, USA, and report frequency of occurrence and relative read abundance. We also assigned seal sex to scat samples using a revised PCR assay. In contrast to current understanding of grey seal diet from hard parts and fatty acid analysis, we found no significant difference between male and female diet measured by alpha and beta diversity. Overall, we detected 24 prey groups, 18 of which resolved to species. Sand lance Ammodytes spp. were the most frequently consumed prey group, with a frequency of occurrence (FO) of 97.3%, consistent with previous studies, but Atlantic menhaden Brevoortia tyrannus, the second most frequently consumed species (FO = 60.8%), has not previously been documented in US grey seal diet. Our results suggest that a metabarcoding approach to seal food habits can yield important new ecological insights, but that traditional hard parts analysis does not underestimate consumption of Atlantic cod Gadus morhua (FO = 6.7%, Gadidae spp.) and salmon Salmo salar (FO = 0%), 2 particularly valuable species of concern.

scholarly journals FEEDING HABITS AND HELMINTH PARASITES OF SARDINE (S. PILCHARDUS) AND ANCHOVY (E. ENCRASICOLUS) IN THE ADRIATIC SEA

2015 ◽  
Vol 17 (1) ◽  
pp. 216 ◽  
Author(s):  
B. ZORICA ◽  
V. ČIKES KEČ ◽  
O. VIDJAK ◽  
I. MLADINEO ◽  
D. EZGETA BALIČ
Keyword(s):  
Diet Composition ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Stomach Content Analysis ◽  
Helminth Parasites ◽  
Significant Difference ◽  
Prey Composition ◽  
One Year ◽  
Paratenic Hosts ◽  
Hysterothylacium Aduncum

We examined the stomach contents of two of the most economically and ecologically important small pelagic fish species, the sardine, Sardina pilchardus and the anchovy, Engraulis encrasicolus, obtained monthly from commercial purse-seine catches operating on Croatian fishing grounds during a one-year period (January–December, 2011). Both species generally showed a similar diet, with copepod and decapod larvae as dominant prey groups. The composition of anchovy and sardine stomach contents was not size- or sex-related, but throughout the year, a significant difference in diet composition was observed for each species as well as between species. Two gastrointerstinal helminths; the digenean Parahemiurus merus and nematode Hysterothylacium aduncum, were recorded during the stomach content analysis. Differences in population dynamics between the two parasites are congruent with differences in the prey composition of sardine and anchovy, reflecting fine-tuned interactions in the trophic web between parasites and intermediate or paratenic hosts included in the sardine and anchovy diet.

scholarly journals Optical axes of catadioptric systems including visual, Purkinje and other nonvisual systems of a heterocentric astigmatic eye

2010 ◽  
Vol 69 (3) ◽  
Author(s):  
W. F. Harris
Keyword(s):  
Visual System ◽  
Optical Axis ◽  
The Other ◽  
Optical Systems ◽  
Numerical Examples ◽  
Straight Line ◽  
Optical Axes ◽  
Catadioptric Systems ◽  
Reflecting Surfaces ◽  
Special Case

For a dioptric system with elements which may be heterocentric and astigmatic an optical axis has been defined to be a straight line along which a ray both enters and emerges from the system.  Previous work shows that the dioptric system may or may not have an optical axis and that, if it does have one, then that optical axis may or may not be unique.  Formulae were derived for the locations of any optical axes.  The purpose of this paper is to extend those results to allow for reflecting surfaces in the system in addition to refracting elements.  Thus the paper locates any optical axes in catadioptric systems (including dioptric systems as a special case).  The reflecting surfaces may be astigmatic and decentred or tilted.  The theory is illustrated by means of numerical examples.  The locations of the optical axes are calculated for seven optical systems associated with a particular heterocentric astigmatic model eye.  The optical systems are the visual system, the four Purkinje systems and two other nonvisual systems of the eye.  The Purkinje systems each have an infinity of optical axes whereas the other nonvisual systems, and the visual system, each have a unique optical axis. (S Afr Optom 2010 69(3) 152-160)

Oscillatory changes in muscle lipoprotein lipase activity of fed and starved rats.

1977 ◽  
Vol 233 (4) ◽  
pp. E316
Author(s):  
T J Kotlar ◽  
J Borensztajn
Keyword(s):  
Lipoprotein Lipase ◽  
Lipase Activity ◽  
Feeding Habits ◽  
Quadriceps Muscle ◽  
Diabetic Rats ◽  
Lipoprotein Lipase Activity ◽  
Nocturnal Feeding ◽  
Ad Libitum ◽  
Short Time ◽  
Fast Twitch

Lipoprotein lipase activity was measured at short time intervals in cardiac and skeletal muscles of normal and streptozotocin-treated diabetic rats fed ad libitum or deprived of food. In normal animals fed ad libitum, lipoprotein lipase activities of heart, diaphragm, soleus, and fast-twitch red fibers of the quadriceps muscle showed rhythmic oscillations that appeared to coincide with the nocturnal feeding habits of the animals. During the day (7 A.M. to 7 P.M.), when food consumption by the rats was greatly reduced, lipoprotein lipase activity in all muscles increased, followed by a decline to basal levels during the night. Similar oscillatory changes in lipoprotein lipase activity were observed in the muscles of diabetic rats fed ad libitum. In normal rats deprived of food, however, the oscillatory changes in muscle lipoprotein lipase activity were not abolished and persisted for at least 48 h. In diabetic rats starved during a 48-h period, the oscillatory changes in muscle lipoprotein lipase activity were markedly altered. In all animals, muscle lipoprotein lipase activities were not correlated to plasma glucagon levels.

Use of epidermal mucus in elasmobranch stable isotope studies: a pilot study using the giant manta ray (Manta birostris)

2018 ◽  
Vol 69 (2) ◽  
pp. 336 ◽  
Author(s):  
K. B. Burgess ◽  
M. Guerrero ◽  
A. J. Richardson ◽  
M. B. Bennett ◽  
A. D. Marshall
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Time Course ◽  
Feeding Habits ◽  
Isotope Analysis ◽  
Δ13c Values ◽  
Significant Difference ◽  
Manta Birostris ◽  
Epidermal Mucus ◽  
Manta Ray

Stable isotope analysis of tissues with different turnover rates allows for a broader temporal view of a species’ feeding habits. Epidermal mucus is a rapid to medium turnover ‘tissue’ in teleost fish, but its use in elasmobranch dietary studies is unknown. In the present study, we conducted stable isotope analysis on mucus and muscle from the giant manta ray Manta birostris. Mucus δ13C values were depleted and closer to surface zooplankton δ13C values compared with muscle, whereas there was no significant difference in δ15N values between these two tissue types. Using diet tissue discrimination factors from the literature, there was no significant difference in the expected prey profile between muscle and epidermal mucus. However, a broader range in δ13C values of expected prey was shown for mucus compared with muscle. The results suggest that if M. birostris mucus is indicative of recent dietary intake, resource use during aggregative behaviour off Ecuador is broader, but with no obvious resource switching. The present study is the first example of using bulk stable isotope analysis to evaluate mucus to investigate feeding ecology in elasmobranchs. However, the time course for the change in mucus isotope signature still needs to be determined through controlled feeding studies in an aquarium setting.

scholarly journals Nasal index among Students of People’s Dental College and Hospital

2019 ◽  
Vol 1 (1) ◽  
pp. 21-27
Author(s):  
Mangesh Bajracharya ◽  
Samjhana Sharma
Keyword(s):  
Ethnic Identity ◽  
Sexual Dimorphism ◽  
Female Students ◽  
Baseline Data ◽  
Craniofacial Surgery ◽  
Male And Female ◽  
Size And Shape ◽  
Gender Differentiation ◽  
Significant Difference ◽  
The Mean

Introduction: Nasal anthropometry is a study that deals with the measurements of the proportion, size, and shape of the nose. The nasal index is considered as one of the major landmarks for craniofacial surgery, gender differentiation, and ethnic identity. This study is aimed to provide baseline data of the nasal index of Nepalese people and to assess the gender variation which will be of clinical, surgical interest in rhinology and craniofacial prosthetic purpose. Methods: BDS students from 17 to 25 years with various ethnicity were included in the study. A total of 160 students with an equal number of male and female students was included. Nasal parameters were measured and the nasal index was calculated for each student. Result: The mean nasal index was 78.03±7.07 suggesting Mesorrhine type of nose. The nasal width and height show statistically significant differences whereas there was no significant difference found between the nasal indices of male and female students. Hill Janajati showed the highest nasal index followed by Newar, Brahmin and Chettri; and Others. Conclusion: The study concludes the type of nose has an effect on gender when compared between the sex but the nasal index calculated to have a little contribution to sexual dimorphism. Mesorrhine nose was found to be most frequent. Among the population, Hill Janajati showed the highest nasal index. We recommend further study to compare the nasal index of various ethnical groups of the Nepalese population. Keywords: Anthropometry, Mesorrhine, Nasal Index

scholarly journals Perbedaan ukuran dan bentuk lengkung gigi antara laki-laki dan perempuan suku Bugis, Makassar, dan Toraja Difference of size and shape of dental arch between male and female of Buginese, Makassarese, and Toraja

2012 ◽  
Vol 11 (3) ◽  
pp. 156 ◽  
Author(s):  
Irene Edith Rieuwpassa ◽  
Syamsiar Toppo ◽  
Sri Dian Haerawati
Keyword(s):  
Observational Study ◽  
Sampling Method ◽  
Cross Sectional Study ◽  
Dental Arch ◽  
Sectional Study ◽  
Cross Sectional ◽  
Men And Women ◽  
Male And Female ◽  
Size And Shape ◽  
Significant Difference

Factors which influence the dental arch changes including genetic and environment. This study aims to determine thedifferences in size and shape of dental arch between men and women of Buginese, Makassarese and Torajanese. Thisstudy is an observational study, with a cross-sectional study design. The sampling method was purposive sampling, andnumber of samples were 90 samples obtained from 90 people with 30 people for each tribe, consist of 15 men and 15women, aged 18-25 years, with full dentition. Data were obtained through tcasting models of the maxillary andmandibular samples then were measured by using a ruler and caliper, then calculated using formula to determine,register, and analyze the size and shape of dental arch. Using multiple statistics, including t-test, ANOVA, chi-squaretest, and marginal of homogenity test there are significant differences regarding the size and shape of dental archbetween men and women of the Buginese, Makassarese, and Torajanese. There is only significant difference ofmaxillary dental arch for Buginese, Makassarese, and Torajanese

scholarly journals Neoteny in visual system development of the spotted unicornfish, Naso brevirostris (Acanthuridae)

2019 ◽  
Author(s):  
Valerio Tettamanti ◽  
Fanny de Busserolles ◽  
David Lecchini ◽  
Justin Marshall ◽  
Fabio Cortesi
Keyword(s):  
Visual System ◽  
System Development ◽  
Feeding Habits ◽  
Quantitative Difference ◽  
Photoreceptor Cells ◽  
Reef Fishes ◽  
Ontogenetic Changes ◽  
Cone Opsin ◽  
Opsin Genes ◽  
Visual System Development

AbstractOntogenetic changes of the visual system are often correlated to shifts in habitat and feeding behaviour of animals. Coral reef fishes begin their lives in the pelagic zone and then migrate to the reef. This transition of habitat frequently involves a change in diet and light environment as well as major morphological modifications. The spotted unicornfish, Naso brevirostris, is known to shift diet from zooplankton to algae and back to zooplankton when transitioning from larval to juvenile and then to adult stages. Concurrently, N. brevirostris also moves from an open pelagic to a coral-associated habitat before migrating up in the water column when reaching adulthood. Using retinal mapping techniques, we discovered that the distribution and density of ganglion and photoreceptor cells in N. brevirostris do not change with the habitat or the feeding habits of each developmental stage. Instead, fishes showed a neotenic development with a slight change from larval to juvenile stages and not many modifications thereafter. Visual gene expression based on RNA sequencing mirrored this pattern; independent of stage, fishes mainly expressed three cone opsin genes (SWS2B, RH2B, RH2A), with a quantitative difference in the expression of the green opsin genes (RH2A and RH2B) when transitioning from larvae to juveniles. Hence, contrary to the ontogenetic changes found in many animals, the visual system is fixed early on in N. brevirostris development calling for a thorough analysis of visual system development of the reef fish community.

scholarly journals Comparative study on the effects of different feeding habits and diets on intestinal microbiota in Acipenser baeri Brandt and Huso huso

2019 ◽  
Author(s):  
Guanling Xu ◽  
Wei Xing ◽  
Tieliang Li ◽  
Min Xue ◽  
Zhihong Ma ◽  
...  
Keyword(s):  
Intestinal Microbiota ◽  
Feeding Habits ◽  
Siberian Sturgeon ◽  
Huso Huso ◽  
Gastrointestinal Microbiota ◽  
Acipenser Baeri ◽  
Significant Difference ◽  
Sh Group ◽  
The Impact ◽  
Beluga Sturgeon

Abstract Background: Siberian sturgeon ( Acipenser baeri Brandt) and Beluga sturgeon ( Huso huso ) are two important commercial fish in China, and the feeding habits of them are very different. Diets and feeding habits are two significant factors to affect the gastrointestinal microbiota in fish. The intestinal microbiota has been reported to play a key role in nutrition and immunity. However, it is rarely reported about the relationship between the intestinal microbiota and feeding habits/diets on different Acipenseridae fish. This study is to comparative analysis of gut microbial community in Siberian sturgeon and Beluga sturgeon fed with the same diet/Beluga sturgeon fed with different diets in order to determine the effects of different feeding habits/diets on the fish intestinal microbiota. Results: According to the experimental objectives, BL and BH groups were Beluga sturgeon ( Huso huso ) fed with low fishmeal diet and high fishmeal diet, respectively. SH group represented Siberian sturgeon ( Acipenser baeri Brandt) fed with the same diet as BH group. After 16 weeks feeding trial, the intestinal microbiota was examined by 16S rRNA high-throughput sequencing technology. On the phylum level, Proteobacteria and Bacteroidetes were significantly higher in BL group than BH group, and Cyanobacteria showed the opposite trend. Compared with BH group, Proteobacteria and Firmicutes were significantly increased in SH group, whereas Cyanobacteria were clearly decreased. At the genus level, Pseudomonas and Citrobacter in BL group were significantly higher comparing with BH group, while Bacillus , Luteibacter , Staphylococcus and Oceanobacillus was lower in BH group than SH group. Conclusions: Alpha and beta diversities indicated that the intestinal microflora were significant difference between Siberian sturgeon and Beluga sturgeon when they fed with the same diet. Meanwhile, Beluga sturgeon fed with low fishmeal diet can increase the species diversity of intestinal microbiota than it fed with high fishmeal diet. Therefore, feeding habits clearly affected the gastrointestinal microbiota of sturgeons. Moreover, the impact of changes in food on the gut microbiota of sturgeons should be taken into consideration during the process of sturgeon aquaculture.

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