X.—On the Feeding Mechanism of a Mysid Crustacean, Hemimysis Lamornæ

1927 ◽  
Vol 55 (1) ◽  
pp. 219-253 ◽  
Author(s):  
H. Graham Cannon ◽  
S. M. Manton

The general biology of the Mysids has recently been studied at great length by Blegvad (1922) at Copenhagen. His paper, containing a very complete literature list, deals with Mysis inermis, Rathke, Mysis flexuosa, Müller, and Mysis neglecta, Sars. His comments on feeding are limited, and refer chiefly to the nature of the food that the animals ate in captivity. Gelderd's work (1909) on the digestive system of the Schizopoda describes the course taken by the food through the gastric mill, the masticatory functions of this apparatus, and the method by which the masticated food and digestive juices are brought together, but does not deal with the manner in which the food reaches the stomach. An account, then, of the method by which a mysid collects its food would fill a gap in our knowledge of these forms. The only description, as far as we are aware, of the feeding habits of a mysid is that of Depdolla (1923), who worked on Praunus [Mysis] flexuosus, but his account is superficial and in our opinion very inaccurate. The following paper deals with the feeding habits of a small mysid, Hemimysis lamornœ, about 8 mm. long, which has established itself in the larger fish-tanks at the M.B.A. laboratory at Plymouth. It breeds freely all the year round, and can be obtained from the tanks in abundance, although it is stated to be only a rare visitor in the Plymouth district.

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Bhaskara Canan ◽  
Wallace Silva do Nascimento ◽  
Naisandra Bezerra da Silva ◽  
Sathyabama Chellappa

This study investigated the morphohistology of the digestive tract and the mean intestinal coefficient of the damsel fishStegastes fuscuscaptured from the tidal pools of Northeastern Brazil. The wall of the digestive tract ofS. fuscusis composed of the tunica mucosa, tunica muscularis, and tunica serosa. The esophagus is short with sphincter and thick distensible wall with longitudinally folded mucosa. Mucous glands are predominant, and the muscular layer of the esophagus presented striated fibers all along its extension. The transition region close to the stomach shows plain and striated muscular fibers. Between the stomach and intestine, there are three pyloric caeca. The intestine is long and thin with four folds around the stomach. The anterior intestine presents folds similar to those of pyloric caeca. The estimated mean intestinal coefficient and characteristics of the digestive system ofS. fuscuspresent morphological adequacy for both herbivorous and omnivorous feeding habits.


2013 ◽  
Vol 22 (3) ◽  
pp. 433-436 ◽  
Author(s):  
Diego Silva da Silva ◽  
Gertrud Müller

This study aimed to identify the parasites that inhabit the digestive system of Sus scrofa scrofa from a commercial breeding facility in southern Brazil, and reports the first occurrence of Trichostrongylus colubriformis in wild boars. The gastrointestinal tracts of 40 wild boars from a commercial breeding facility were collected and individualized during slaughter in a cold-storage slaughterhouse. Out of this total, 87.5% were parasitized by the helminths Ascaris suum,Trichostrongylus colubriformis, Oesophagostomum dentatum and Trichuris suis. T. colubriformis presented a prevalence of 45%, mean intensity of 28.4 and mean abundance of 12.8. The data from this study showed that T. colubriformis not only has a capacity to develop in the small intestines of wild boars, but also adapts well to animals raised in captivity, thus representing a possible cause of economic loss in commercial wild boar farming.


1938 ◽  
Vol 59 (2) ◽  
pp. 267-307 ◽  
Author(s):  
Alastair Graham

During recent years there has been a very great advance in our knowledge of the minute structure and function of the various regions and glands of the alimentary canal of the prosobranch and pulmonate gastropods, without any corresponding increase in our understanding of the opisthobranch and, in particular, of the nudibranch gut. That the emphasis should be laid on the streptoneurous and the land-living forms is obviously due to their abundance and to the fact that they include almost all the familiar types of gastropod mollusc, but it is disappointing that, at the moment of writing, there exists only one account of the histology and function of the digestive system of either a dorid or an æolid—to confine attention to the two main types of nudibranch molluscs which occur in British waters—that of Millott (1937b). This is perhaps more noticeable when it is recalled that the nudibranchs have specialised along distinctly unusual lines, many of which are intimately associated with the food and feeding habits which the animals have adopted. The æolids, it is true, have attracted a lively interest in connexion with their possession of nematocysts, but the majority of investigators have apparently been content to trace these into the cnidosacs without concerning themselves over the other constituents of the animal's food.


2006 ◽  
Vol 274 (1610) ◽  
pp. 635-640 ◽  
Author(s):  
Oliver Wings ◽  
P. Martin Sander

Polished pebbles occasionally found within skeletons of giant herbivorous sauropod dinosaurs are very likely to be gastroliths (stomach stones). Here, we show that based on feeding experiments with ostriches and comparative data for relative gastrolith mass in birds, sauropod gastroliths do not represent the remains of an avian-style gastric mill. Feeding experiments with farm ostriches showed that bird gastroliths experience fast abrasion in the gizzard and do not develop a polish. Relative gastrolith mass in sauropods (gastrolith mass much less than 0.1% of body mass) is at least an order of magnitude less than that in ostriches and other herbivorous birds (gastrolith mass approximates 1% of body mass), also arguing against the presence of a gastric mill in sauropods. Sauropod dinosaurs possibly compensated for their limited oral processing and gastric trituration capabilities by greatly increasing food retention time in the digestive system. Gastrolith clusters of some derived theropod dinosaurs (oviraptorosaurs and ornithomimosaurs) compare well with those of birds, suggesting that the gastric mill evolved in the avian stem lineage.


2021 ◽  
Vol 9 ◽  
Author(s):  
Shumin Liu ◽  
Zhiheng Li ◽  
Alida M. Bailleul ◽  
Min Wang ◽  
Jingmai O’Connor

Gastroliths, where preserved, can provide indirect evidence regarding diet in extinct avian and non-avian dinosaurs. Masses of gastroliths consistent with the presence of a gastric mill are preserved in many Early Cretaceous Jehol birds mostly belonging to the Ornithuromorpha. Gastroliths are also present in basal birds Sapeornis and Jeholornis in which herbivory is supported by direct evidence these taxa consumed seeds in the form of crop or stomach contents. Although gastroliths have been correlated with herbivory in non-avian dinosaurs, the presence of gastroliths and bone together in Ambopteryx calls this association in to question. Despite being known from greater numbers of specimens than other avian lineages, no unequivocal direct or indirect evidence of diet has been recovered from Jehol deposits for the Enantiornithes. A referred specimen of Bohaiornis guoi IVPP V17963 was described as preserving a small number of gastroliths interpreted as rangle, gastroliths whose function is cleaning the stomach in extant raptorial birds. However, based on comparison with gastroliths in other Jehol birds, it has alternatively been suggested that the identified structures are not ingested stones at all but some unusual mineral precipitate. Considering the limited evidence regarding diet in Enantiornithes and the importance of accurately identifying the traces in Bohaiornis in order to understand the enantiornithine digestive system, we extracted two samples of these purported gastroliths and explored these traces using computerized laminography scanning, scanning electron microscopy, energy dispersive x-ray spectroscopy, ground sections, and body size to gastral mass regressions. Similar analyses were conducted on gastroliths extracted from undisputed gastral masses of two Jehol ornithuromorphs and the non-avian pennaraptoran Caudipteryx. The combined results contradict the hypothesis that these traces are gastroliths and supports the interpretation they are mineral precipitate, most likely authigenic quartz (chalcedony). Although authigenesis is commonly responsible for the preservation of soft tissues, it is unclear if these traces record part of the tissues of this Bohaiornis. This study highlights the importance of a multidisciplinary approach in understanding unusual traces in the fossil record and reveal a previously unidentified taphonomic phenomenon in fossils from Jehol deposits.


Author(s):  
Edith A. T. Nicol

The Galatheidea are divided into two families, the Galatheidæ and the Porcellanidæ, which differ from each other in their feeding habits as well as their structure.Galathea dispersa has been taken as typical of the Galatheidæ. An examination of the gut contents shows that the food in the stomach consists of finely divided particles mixed with sand and detritus. In addition larger pieces of animal and vegetable matter are occasionally found. Observations of the animals in captivity show that they feed by two methods; either large pieces of food are seized by the chelæ and maxillipeds and passed to the mandibles or, as is more usual, the third maxillipeds are used to collect finely divided material from the substratum.The setæ on the terminal segments of the maxillipeds form a dense tuft which sweeps over the substratum, loosening and collecting small particles. The terminal tufts are cleaned out by the setse of the second maxillipeds, and the food passed to the mouth.


Insects ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 530
Author(s):  
Maria Dally ◽  
Maya Lalzar ◽  
Eduard Belausov ◽  
Yuval Gottlieb ◽  
Moshe Coll ◽  
...  

Bacterial symbionts in arthropods are common, vary in their effects, and can dramatically influence the outcome of biological control efforts. Macrolophus pygmaeus (Heteroptera: Miridae), a key component of biological control programs, is mainly predaceous but may also display phytophagy. M. pygmaeus hosts symbiotic Wolbachia, which induce cytoplasmic incompatibility, and two Rickettsia species, R. bellii and R. limoniae, which are found in all individuals tested. To test possible involvement of the two Rickettsia species in the feeding habits of M. pygmaeus, we first showed that the microbiome of the insect is dominated by these three symbionts, and later described the distribution pattern of the two Rickettsia species in its digestive system. Although both Rickettsia species were located in certain gut bacteriocyes, in caeca and in Malpighian tubules of both sexes, each species has a unique cellular occupancy pattern and specific distribution along digestive system compartments. Infrequently, both species were found in a cell. In females, both Rickettsia species were detected in the germarium, the apical end of the ovarioles within the ovaries, but not in oocytes. Although the cause for these Rickettsia distribution patterns is yet unknown, it is likely linked to host nutrition while feeding on prey or plants.


Author(s):  
Natassia Bacco Mannina ◽  
Daniela Magalhães Drummond de Mello ◽  
Rebeca Pires Wanderley

This report describes the successful rehabilitation of two species of pelagic seabirds (Macronectes halli and Macronectes giganteus) rescued on the southern coast of the state of São Paulo, Brazil, and taken to the IPeC rehabilitation center (S25°023258 W-47°928737). Data on the enclosures, diet, clinical management and laboratory tests were detailed during the 75 d of treatment, during which the birds remained at the center. This report demonstrates that a combination of environmental and nutritional management with a proper diagnosis and adequate clinical treatment naturally lead to a shorter period in captivity, which is crucial to the successful rehabilitation of these birds. The enclosures should have visual isolation and animals kept separate from other birds. The form of offering food differs based on the feeding habits and taxon. At the time of release back into the wild, the site chosen should be isolated to enable the bird to feel more secure when taking flight. The present report describes the first record of the rehabilitation and release of these two species in Brazil.


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