scholarly journals Diet preferences of the Aglajidae: a family of cephalaspidean gastropod predators on tropical and temperate shores

2015 ◽  
Vol 96 (5) ◽  
pp. 1101-1112 ◽  
Author(s):  
Andrea Zamora-Silva ◽  
Manuel António E. Malaquias
Keyword(s):  
Electron Microscopy ◽  
Adaptive Radiation ◽  
Food Habits ◽  
Digestive System ◽  
Trophic Niche ◽  
Gut Contents ◽  
Feeding Mode ◽  
Dietary Specialization ◽  
Food Items ◽  
Scanning Electron

Aglajidae is a family of tropical and temperate marine Cephalaspidea gastropod slugs regarded as active predators. In order to better understand their food habits and trophic interactions, we have studied the diet of all genera through the examination of gut contents. Specimens were dissected for the digestive tract and gut contents were removed and identified by optical and scanning electron microscopy. Our results confirmed that carnivory is the only feeding mode in aglajids and showed a sharp preference for vagile prey (94% of food items). We suggest that the interaction between crawling speed, presence of sensorial structures capable of detecting chemical signals from prey, and unique features of the digestive system (e.g. lack of radula, eversion of the buccal bulb, thickening of gizzard walls) led aglajid slugs to occupy a unique trophic niche among cephalaspideans, supporting the hypothesis that dietary specialization played a major role in the adaptive radiation of Cephalaspidea gastropods.

Microbial Flora Associated with the Digestive System ofUpogebia Stellata(Crustacea: Decapoda: Thalassinidea)

1997 ◽  
Vol 77 (4) ◽  
pp. 1083-1096 ◽  
Author(s):  
E.H. Pinn ◽  
A. Rogerson ◽  
R.J.A. Atkinson
Keyword(s):  
Electron Microscopy ◽  
Digestive System ◽  
Bacterial Population ◽  
Bacterial Isolate ◽  
Epifluorescence Microscopy ◽  
Microbial Populations ◽  
Gut Contents ◽  
Bacterial Isolates ◽  
Dramatic Rise ◽  
Scanning Electron

The digestive system of the thalassinidean mud-shrimpUpogebia stellatawas investigated using scanning electron microscopy (SEM). Within the lumen of the midgut both filamentous and rod-shaped bacteria were observed. The hindgut microbial populations were dominated by dense mats of epimural rod-shaped bacteria. The gut contents were often dominated by diatoms but also contained bacteria, dinoflagellates, plant and algal fragments. Direct bacterial counts by epifluorescence microscopy along the length of the gut revealed a slight decrease in numbers within the midgut moving from the anterior to the posterior regions, and then a dramatic rise in numbers within the hindgut. Numbers decreased again in the posterior regions of the hindgut. Common in the transient / resident samples (bacterial population when gut contents were present) were enterobacteria and an unidentified fermenter conforming to an isolate named X-ferm. However, nearly 30% of the bacterial isolates remained unidentified. The resident-only bacterial isolates from the gut (determined when the gut was empty) were dominated by the X-ferm bacteria and to a lesser extent by the generaVibrioandAeromonas. With respect to the enzyme capabilities of the gut bacteria, the resident-only collection of bacterial isolates showed much higher levels of amylase, cellulase, chitinase, protease and lipase activity than the transient/resident bacterial isolate collections, suggesting that the indigenous bacteria are likely to play a significant role in the digestion of the gut contents. Thalassinidean shrimps are likely to play an important role in the breakdown of plant and detrital material, and the recycling of nutrients in marine benthic systems.

Character analysis of adaptations for tarsal pollen collection in the Bombyliidae (Insecta: Diptera): the benefits of putting your foot in your mouth

Zootaxa ◽  
2003 ◽  
Vol 157 (1) ◽  
pp. 1 ◽  
Author(s):  
JOHN L. NEFF ◽  
BERYL B. SIMPSON ◽  
NEAL L. EVENHUIS ◽  
GREGG DIERINGER
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Gut Contents ◽  
Character Analysis ◽  
Pollen Collection ◽  
Direct Observations ◽  
Pollen Feeding ◽  
The Family ◽  
Scanning Electron

Using direct observations and analyses of gut contents, we document that pollen feeding is widespread among female bombyliid flies. Pollen feeding is typically indirect with the initial pollen acquisition accomplished by foretarsal stroking of the anthers. Observations of the foretarsi using light and scanning electron microscopy showed that the foretarsi bear modified setae that play a role in pollen collection. Across the family, we found considerable variation in the morphology and distribution of the foretarsal setae that appear to be more related to phylogeny than pollen host. The major patterns of foretarsal setal specialization are illustrated and discussed.

Parasitic copepods in the sea hare Dolabrifera brazieri (Gastropoda: Opisthobranchia: Anaspidea)

2003 ◽  
Vol 83 (4) ◽  
pp. 793-796 ◽  
Author(s):  
Cathryn L. Clarke ◽  
Annette Klussmann-Kolb
Keyword(s):  
Electron Microscopy ◽  
New South ◽  
Gill Tissue ◽  
Parasitic Copepod ◽  
Feeding Mode ◽  
Histological Techniques ◽  
Parasitic Copepods ◽  
Sea Hare ◽  
South Wales ◽  
Scanning Electron

The parasitic copepod, Alimeda orientalis, is recorded from the gill of the sea hare, Dolabrifera brazieri (Gastropoda: Opisthobranchia: Anaspidea). Ten specimens of D. brazieri from a population on the coast of New South Wales, Australia were examined for the incidence of parasitism. Histological techniques and scanning electron microscopy were utilized to determine the feeding mode of A. orientalis and its effect on the host. Alimeda orientalis is a tissue feeder on the gill tissue, and damage caused by feeding and attachment is minimal.

scholarly journals On the natural diet of Daphnia laevis in the eutrophic Pampulha reservoir (Belo Horizonte, Minas Gerais)

2002 ◽  
Vol 62 (3) ◽  
pp. 445-452 ◽  
Author(s):  
E. M. ESKINAZI-SANT'ANNA ◽  
P. M. MAIA-BARBOSA ◽  
F. A. R. BARBOSA
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Food Item ◽  
Inorganic Material ◽  
Minas Gerais ◽  
Gut Contents ◽  
Gut Content ◽  
Natural Diet ◽  
Belo Horizonte ◽  
Scanning Electron

The aim of this study was to assess the major food items ingested by adult specimens of Daphnia laevis within the eutrophic Pampulha reservoir in Belo Horizonte, Minas Gerais, Brazil. The gut content was analyzed after addition of sodium hypochlorite and also through the examination of dissected guts under scanning electron microscopy. The results showed that Chlorophyceae was the main food item ingested, representing c. 80.5% of the total ingested food. Moreover, Eutetramorus fottii, Coelastrum pseudomicroporum and Oocystis lacustris, the dominant phytoplankton species within the reservoir, were the most frequent cells found in the gut contents. Euglenophyta also represented an important food item accounting for 15% of the ingested material, including mainly Trachelomonas volvocina and Euglena oxyuris, although less abundant in the reservoir (< 10% of total phytoplankton). Blue-green algae occurred at much lower percentages in the guts than in the phytoplankton. A small amount of undigested Microcystis aeruginosa colonies were also found in the gut content of D. laevis. Scanning electron microscopy results showed that, besides phytoplankton cells, a great amount of abiogenic material was also ingested. The amount of this inorganic material increased considerably in the tract (from 15% to 75% of the gut content), when a peak of D. laevis was observed in the reservoir. Our assumption is that the ingestion of this inorganic material can be a strategy used by D. laevis to obtain additional food supply.

scholarly journals Does male Chondracanthus lophii (Crustacea: Copepoda) feed?

2004 ◽  
Vol 84 (4) ◽  
pp. 711-716 ◽  
Author(s):  
Pia Østergaard
Keyword(s):  
Electron Microscopy ◽  
B Cell ◽  
Digestive System ◽  
Light And Electron Microscopy ◽  
Gut Contents ◽  
Type B ◽  
Internal Anatomy ◽  
Cell Type ◽  
Blind Ending ◽  
Active Feeding

Male Chondracanthus lophii was studied using light and electron microscopy. Observations on external morphology and internal anatomy are presented. Males possess a full set of functional mouth parts, the digestive system is active and the dominant cell type in the midgut is identified as the vacuolar type B-cell, but the gut is a blind ending sac with no anus. The gut contents were a homogenous, amorphous mass. The combination of active feeding and digestion with a blind ending gut supports the inference that males feed on special secretions produced by glands in the nuptial organs of the female. It is speculated that dependence on such secretion reduces or eliminates the production of faecal matter. Observations on the reproductive system confirmed the typical chondracanthid pattern.

scholarly journals A New Look at Old Beer and Bread

1996 ◽  
Vol 4 (7) ◽  
pp. 3-5
Author(s):  
Stephen W. Carmichael
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ancient Egypt ◽  
Cambridge University ◽  
Food Items ◽  
The People ◽  
Dry Conditions ◽  
Scanning Electron ◽  
New Look

We know from the pictographic history that the people in ancient Egypt were fond of beer and bread. Fortunately, they sent samples of these food items along with some of their more esteemed citizens to sustain them in the afterlife. Also, samples were available from rubbish heaps of ancient villages, allowing for the comparison of funerary goods with everyday foods. Additional luck was that the dry conditions have kept some samples from deteriorating even after thousands of years. Whereas they did leave us samples, they didn't leave recipes. There have been many theories about how they brewed and baked in ancient Egypt, but proof was lacking. Recently, Delwen Samuel of Cambridge University used optical and scanning electron microscopy (SEM) to determine how the ancient Egyptians brewed beer and baked bread.

Relevant role of the labrum associated with the mandibles in the Lophogaster typicus digestive function

2002 ◽  
Vol 82 (2) ◽  
pp. 219-227 ◽  
Author(s):  
L. De Jong ◽  
X. Moreau ◽  
R.-M. Barthélémy ◽  
J.-P. Casanova
Keyword(s):  
Electron Microscopy ◽  
Endocrine Cells ◽  
Morphological Data ◽  
Gut Contents ◽  
Digestive Function ◽  
Relevant Role ◽  
External Face ◽  
Incisor Process ◽  
Scanning Electron

This study was aimed at understanding the diet and the digestive function of the deep-living Lophogastrida species Lophogaster typicus (Mysidacea: Lophogastrida). Scanning electron microscopy (SEM) investigations have revealed that the mandibles exhibit typical features of a carnivorous diet, i.e. large and sharp incisor process and small molar one with only few scales. The analysis of gut contents confirms morphological data as crustacean remains have been recognized. However, the presence of a large quantity of unidentifiable soft particulate matter also indicates a saprophagous tendency. The external asymmetrical edge of the labrum consists of a small grinding area. The entire external face of the labrum exhibits numerous pores, which are related with glandular units. These units are organized into acini of two to four large cells. Two types of acini have been observed, i.e. with dark or clear cells. According to ultrastructural and cytochemical data, labral secretions are believed to be mucopolysaccharidic (for clear acini) and enzymatic components (for dark acini), and are therefore involved both in coating and in digesting the food. Moreover, presence of neuronal endings and endocrine cells, both associated with glandular units, and comparison between glandular units in starved and fed animals suggest a controlled release of the secretions. Therefore, the labrum plays a crucial role in the digestive function of the lophogastrid crustacean L. typicus, as it involves both mechanical and chemical breakdown of the food.

Northern Squawfish (Ptychocheilus oregonensis) Predation on Juvenile Salmonids in Sections of the Willamette River Basin, Oregon

1981 ◽  
Vol 38 (3) ◽  
pp. 360-364 ◽  
Author(s):  
David V. Buchanan ◽  
Robert M. Hooton ◽  
John R. Moring
Keyword(s):  
River Basin ◽  
Food Habits ◽  
Stomach Contents ◽  
Lag Time ◽  
Food Type ◽  
Gut Contents ◽  
Sampling Techniques ◽  
Willamette River ◽  
Food Items ◽  
Willamette River Basin

Predation by northern squawfish (Ptychocheilus oregonensis) on salmonids was studied in spring months in several lower, free-flowing areas of the Willamette River drainage, Oregon. During 1976 and 1977, 1127 northern squawfish were collected by electrofishing and seining, and examined for food contents. Almost 59% of the squawfish stomachs contained food items, but only 2% contained salmonids. Principal foods were insects, crayfish, and sculpins (Cottidae), and the majority (over 90%) of squawfish had not consumed more than one principal food type. We suggest that previous reports of squawfish predation in flowing rivers were misleading because they were often based on artificial situations (below dams or in waters following hatchery releases) which could have inflated salmonid predation values. Further, the true predatory nature of squawfish is clouded because of their rapid digestion of food and the long lag time in examination of gut contents by previous researchers. Our sampling techniques avoided these shortcomings by sampling in free-flowing areas and by examining squawfish stomach contents immediately after capture.Key words: squawfish, Ptychocheilus oregonensis; predation, food habits, Oregon

A new species of cave dwelling Neocarus (Acari: Opilioacaridae) from Bahia state, Brazil, with remarks on taxonomic characters

Zootaxa ◽  
2018 ◽  
Vol 4402 (2) ◽  
pp. 303 ◽  
Author(s):  
MARCEL SANTOS DE ARAÚJO ◽  
MARIA ELINA BICHUETTE ◽  
GARY R. BAUCHAN ◽  
RONALD OCHOA ◽  
REINALDO JOSÉ FAZZIO FERES
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Karst Area ◽  
Gut Contents ◽  
Species Differentiation ◽  
Dorsal Shield ◽  
Temperature Scanning ◽  
Microscopy Techniques ◽  
A New Species ◽  
Scanning Electron

Neocarus coronatus n. sp., is described from caves and the surrounding epigean habitats from a karst area of São Desidério county, Bahia state, Brazil. A dissection procedure is presented for the better use of scarce Opilioacaridae material, especially to analyze gut contents. Sexual dimorphism is presented, mainly differences in the density of setae on the dorsal shield in the prominent triangular anterior region. Females have an ovipositor with 3 pairs of smooth digitiform projections and 6–8 eugenital setae. Adults have a palpal tibiotarsus with 4 d setae. Using Low-Temperature Scanning Electron Microscopy (LT-SEM), evaluation of the chaetotaxy (especially setal shape) and morphology are greatly improved over standard light microscopy techniques enhancing the interpretation of characters for species differentiation. Also, we discuss the fragility of microinvertebrates in cave habitats. 

scholarly journals Evidence of a dorsal pharynx in the marine polychaete Capitella teleta (Polychaeta: Capitellidae)

Zoosymposia ◽  
2009 ◽  
Vol 2 (1) ◽  
pp. 317-328 ◽  
Author(s):  
MICHAEL J. BOYLE ◽  
ELAINE C. SEAVER
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Buccal Cavity ◽  
Feeding Mode ◽  
Marine Habitats ◽  
Marine Polychaete ◽  
Pharyngeal Gland ◽  
Capitella Teleta ◽  
Selection Of ◽  
Scanning Electron

Observations from compound, confocal, and scanning electron microscopy reveal that the buccal organ in Capitella teleta Blake, Grassle & Eckelbarger, 2009 should be classified as a dorsal pharynx. This buccal organ is an eversible proboscis that has the following characters: (1) dorsal ciliated pad, (2) well-developed pharyngeal retractor muscles, (3) pharyngeal gland-like structures, (4) cuticular fold surrounding the dorsal ciliated pad, and (5) unciliated buccal cavity and anterior ventral epithelium. All of these features are characteristic of dorsal pharyngeal organs present in oligochaetes and one terrestrial polychaete. Our observations in C. teleta confirm the presence of a dorsal pharynx in larvae, juveniles, and adults. C. teleta is a subsurface deposit feeder and a dorsal pharynx may have evolved independently in Capitellidae through selection of feeding mode in benthic marine habitats. Our results represent the first detailed description of a dorsal pharynx in a marine polychaete.

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