scholarly journals Role of the larval feeding morphology and digestive enzyme activity in the early development of the polychaete Boccardia wellingtonensis

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6151 ◽  
Author(s):  
Daniel Doherty-Weason ◽  
Fernanda X. Oyarzun ◽  
Luciano Vera ◽  
Miguel Bascur ◽  
Fabián Guzmán ◽  
...  
Keyword(s):  
Digestive Enzymes ◽  
Life Histories ◽  
Marine Invertebrates ◽  
Digestive Enzyme ◽  
Feeding Strategies ◽  
Larval Feeding ◽  
Stage Of Development ◽  
Planktotrophic Larvae ◽  
Morphological Differences

In marine invertebrates, the modes of development at early stages are related to the type and capacity of larval feeding to achieve growth. Therefore, studying the factors that determine larval feeding strategies can help to understand the diversity of life histories and evolution of marine invertebrates. The polychaete Boccardia wellingtonensis is a poecilogonous species that encapsulates and incubates its offspring. This species produces two types of larvae: (1) larvae that do not feed within the capsule and hatch as planktotrophic larvae (indirect development), and (2) adelphophagic larvae that feed on nurse eggs and other larvae inside the capsule to hatch as advanced larvae or juveniles (direct development). Otherwise, the larval types are indistinguishable at the same stage of development. The non-apparent morphological differences between both types of larvae suggest that other factors are influencing their feeding behavior. This work studied the potential role of the activity of 19 digestive enzymes on the different feeding capacities of planktotrophic and adelphophagic larvae of B. wellingtonensis. Also, differences in larval feeding structures and the larval capacity to feed from intracapsular fluid were evaluated by electron and fluorescence microscopy. Results showed that both types of larvae present similar feeding structures and had the capacity to ingest intracapsular fluid protein. Adelphophagic larvae showed overall the highest activities of digestive enzymes. Significant differences between larval types were observed in nine enzymes related to the use of internal and external nutritional sources. Given that larval feeding is closely related to larval development in species with encapsulation, this work supports that the study of the digestive enzymatic machinery of larvae may contribute to understanding the evolution of developmental modes.

Larvae and Direct Development

2018 ◽  
pp. 151-178
Author(s):  
Richard R. Strathmann
Keyword(s):  
Larval Stage ◽  
Life Histories ◽  
Marine Invertebrates ◽  
Larval Feeding ◽  
Evolutionary Transitions ◽  
Evolutionary Origins ◽  
Marine Crustaceans ◽  
Oxygen Capacity ◽  
Marine Larvae ◽  
Maternal Protection

Modes of development of marine crustaceans and other marine invertebrates include presence or absence of a larval stage, of larval feeding, and of maternal protection of offspring. These different developmental modes impose different compromises (trade-offs) between the number of offspring and their size or the extent of maternal protection. Crustaceans differ from many marine animals in not shedding eggs prior to fertilization, which eliminates the complication of selection on size of eggs as a target for sperm. Features shared with marine invertebrates of several phyla include rare and ancient origins of feeding larvae, irreversible losses of a feeding larval stage, a constraint on brooding imposed by embryos’ need for oxygen, and possible benefits from slower development of protected embryos. Crustaceans differ, however, in having a diverse exoskeletal tool kit that has provided unusual capabilities. Nauplii and zoeae are diverse in form, behavior, and habitat, despite each being nominally one type of larva. Nauplii, as feeding larvae, have adapted to both the benthos and plankton. Settling stages (cyprids and decapodids) with enhanced speed have evolved twice. Some very large adults can supply their large broods with oxygen. Capacity for defense of offspring and home has led a few times to eusociality. The need to molt to grow and change form imposes episodic risk and growth and, in some cases, links evolution of egg size and size at metamorphosis. Crustaceans’ diverse life histories enable comparisons with broad implications for marine invertebrates: opportunity for dispersal is similar for larvae and adults of some crustaceans, demonstrating that marine larvae need not be adaptations for dispersal; development from very small eggs is enabled by less equipment needed for first larval feeding and also by postlarval stages being parasites; eggs shed into the water suffer greater mortality than planktonic larvae or brooded eggs, yet some planktonic crustaceans depend on benthic resting eggs for persistence of populations; larvae escape predation in diverse ways, and bigger larvae are not consistently safer; predation near the seafloor makes settlement a risky stage. Parallels with other taxa are numerous, but the crustacean exoskeletal tool kit has conferred unusual evolutionary opportunities and constraints. Even among marine crustaceans, however, evolutionary options for life histories differ among clades because of rare evolutionary origins of traits of larvae and mothers and biased evolutionary transitions in those traits.

scholarly journals Discovery of digestive enzymes in carnivorous plants with focus on proteases

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4914 ◽  
Author(s):  
Rishiesvari Ravee ◽  
Faris ‘Imadi Mohd Salleh ◽  
Hoe-Han Goh
Keyword(s):  
Digestive Enzymes ◽  
Recent Progress ◽  
Digestive Enzyme ◽  
Industrial Applications ◽  
Carnivorous Plants ◽  
Pitcher Plants ◽  
Enzyme Discovery ◽  
Plant Proteases ◽  
Recombinant Technology

BackgroundCarnivorous plants have been fascinating researchers with their unique characters and bioinspired applications. These include medicinal trait of some carnivorous plants with potentials for pharmaceutical industry.MethodsThis review will cover recent progress based on current studies on digestive enzymes secreted by different genera of carnivorous plants:Drosera(sundews),Dionaea(Venus flytrap), Nepenthes(tropical pitcher plants),Sarracenia(North American pitcher plants), Cephalotus(Australian pitcher plants), Genlisea(corkscrew plants),andUtricularia(bladderworts).ResultsSince the discovery of secreted protease nepenthesin inNepenthespitcher, digestive enzymes from carnivorous plants have been the focus of many studies. Recent genomics approaches have accelerated digestive enzyme discovery. Furthermore, the advancement in recombinant technology and protein purification helped in the identification and characterisation of enzymes in carnivorous plants.DiscussionThese different aspects will be described and discussed in this review with focus on the role of secreted plant proteases and their potential industrial applications.

Influences of Diet on the Life Histories of Aquatic Insects

1979 ◽  
Vol 36 (3) ◽  
pp. 335-342 ◽  
Author(s):  
N. H. Anderson ◽  
Kenneth W. Cummins
Keyword(s):  
Food Quality ◽  
Aquatic Insects ◽  
Life Histories ◽  
Functional Feeding Groups ◽  
Feeding Strategies ◽  
Laboratory Studies ◽  
Benthic Species ◽  
Food Quantity ◽  
Effects Of Temperature

Benthic species are partitioned into functional feeding groups based on food-acquiring mechanisms. Effects of food quality on voltinism, growth rate, and size at maturity are demonstrated for representatives of gougers and shredders, collectors, and scrapers. Food quality for predators is uniformly high, but food quantity (prey density) obviously influences their life histories. A food switch from herbivory to predation, or some ingestion of animal tissues, in the later stages is a feature of the life cycle of many aquatic insects. Temperature interacts with both food quality and quantity in effects on growth as well as having a direct effect on control of metabolism. Thus further elaboration of the role of food in life history phenomena will require controlled field or laboratory studies to partition the effects of temperature and food. Key words: aquatic insects, feeding strategies, functional groups, life histories

The role of dispersal and retention in the early life stages of shrimp in a lowland river

2010 ◽  
Vol 67 (4) ◽  
pp. 720-729 ◽  
Author(s):  
Amina E. Price ◽  
Paul Humphries
Keyword(s):  
Life History ◽  
Life Histories ◽  
Movement Patterns ◽  
Early Ontogeny ◽  
Small Scale ◽  
Lowland River ◽  
Southeastern Australia ◽  
Stage Of Development ◽  
Paratya Australiensis

This study investigated the importance of dispersal and retention processes during early ontogeny for three caridean shrimp species that complete their entire life history in freshwater. Directional traps were used to examine the small-scale movement patterns of shrimp into and out of nursery habitat patches (slackwaters) in a small lowland river in southeastern Australia. Movement patterns provided evidence for two contrasting life history based dispersal and retention strategies. For the two smaller atyid species, Paratya australiensis and Caridina mccullochi , the majority of larvae remained within the slackwater in which they were hatched until the final stage of development, at which point dispersal, either among slackwaters or out of slackwaters to faster-flowing pool and run habitats, occurred. For the larger palaemonid species, Macrobrachium australiense , larvae were hatched into slackwaters and dispersal occurred predominately during the first stage of larval development and then decreased as development progressed. Despite the differences in dispersal strategies among species, movement was mostly associated with a particular larval stage and thus emphasizes the importance of retention during critical developmental periods and of the potential impact that flow alteration could have on these and other species with similar life histories.

Amazing pancreas: specific regulation of pancreatic secretion of individual digestive enzymes in rats

1995 ◽  
Vol 268 (2) ◽  
pp. E349-E359 ◽  
Author(s):  
D. Maouyo ◽  
J. Morisset
Keyword(s):  
Pancreatic Secretion ◽  
Digestive Enzymes ◽  
Jugular Vein ◽  
Digestive Enzyme ◽  
Experimental Period ◽  
The Other ◽  
Exocrine Pancreatic Secretion ◽  
Specific Regulation ◽  
The Relationship

We investigated the effects of somatostatin (SMS)-201-995, atropine, and MK-329 on the role of cholinergic- and cholecystokinin-related systems and on the secretory relationship between five pancreatic digestive enzymes in rats. Animals kept in restraint cages and provided with pancreatic, biliary, duodenal, and jugular vein cannulas were treated as follows: 1) 0.25 micrograms.kg-1.h-1 caerulein alone, 2) both 0.25 micrograms.kg-1.h-1 caerulein and 100 micrograms.kg-1.h-1 atropine, 3) both caerulein and 5 micrograms.kg-1.h-1 SMS, 4) 91.3 micrograms.kg-1.h-1 carbachol alone, 5) both carbachol and 0.5 mg.kg-1.h-1 MK-329, and 6) both carbachol and 5 micrograms.kg-1.h-1 SMS, respectively. Food, but not water, was denied rats starting 10 h before the experiment and throughout the 6-h experimental period. The secretory patterns over the 6-h experimental period showed noticeably independent regulation of pancreatic secretion of individual digestive enzymes. The relationship between paired enzymes significantly varied according to the treatment. The correlation between chymotrypsinogen and the other enzymes was markedly modulated by MK-329. Our results suggest that SMS is a major "gate-keeper" in the regulation of exocrine pancreatic secretion and that the secretion of each digestive enzyme is individually regulated. Furthermore, they suggest that cholecystokinin and acetylcholine and their respective agonists are essentially initiators of secretory processes of the pancreas. Therefore, the paradigms of the regulation of pancreatic secretion heretofore accepted should be reexamined.

scholarly journals Discovery of digestive enzymes in carnivorous plants with focus on proteases

2018 ◽  
Author(s):  
Rishiesvari Ravee ◽  
Faris ‘Imadi Mohd Salleh ◽  
Hoe-Han Goh
Keyword(s):  
Digestive Enzymes ◽  
Recent Progress ◽  
Digestive Enzyme ◽  
Industrial Applications ◽  
Carnivorous Plants ◽  
Pitcher Plants ◽  
Enzyme Discovery ◽  
Plant Proteases ◽  
Recombinant Technology

Background. Carnivorous plants have been fascinating researchers with their unique characters and bioinspired applications. These include medicinal trait of some carnivorous plants with potentials for pharmaceutical industry. Methods. This review will cover recent progress based on current studies on digestive enzymes secreted by different genera of carnivorous plants: Drosera (sundews), Dionaea (Venus flytrap), Nepenthes (tropical pitcher plants), Sarracenia (North American pitcher plants), Cephalotus (Australian pitcher plants), Genlisea (corkscrew plants), and Utricularia (bladderworts). Results. Since the discovery of secreted protease nepenthesin in Nepenthes pitcher, digestive enzymes from carnivorous plants have been the focus of many studies. Recent genomics approaches have accelerated digestive enzyme discovery. Furthermore, the advancement in recombinant technology and protein purification helped in the identification and characterisation of enzymes in carnivorous plants. Discussion. These different aspects will be described and discussed in this review with focus on the role of secreted plant proteases and their potential industrial applications.

scholarly journals Increasing Hormonal Control of Skeletal Development: An Evolutionary Trend in Amphibians

2021 ◽  
Vol 9 ◽  
Author(s):  
Anna B. Vassilieva ◽  
Sergei V. Smirnov
Keyword(s):  
Life Histories ◽  
Skeletal Development ◽  
Experimental Studies ◽  
Hormonal Control ◽  
Regulatory Function ◽  
Evolutionary Trend ◽  
Skull Morphology ◽  
Stage Of Development ◽  
Morphological Studies

The biphasic life history of amphibians includes metamorphosis, a complex developmental event that involves drastic changes in the morphology, physiology and biochemistry accompanying the transition from the larval to adult stage of development. Thyroid hormones (THs) are widely known to orchestrate this remodeling and, in particular, to mediate the development of the bony skeleton, which is a model system in evolutionary morphological studies of amphibians. Detailed experimental studies of the role of THs in the craniogenesis of diverse urodelan amphibians revealed that (i) these hormones affect both the timing and sequence of bone formation, (ii) TH involvement increases in parallel with the increase in divergence between larval and adult skull morphology, and (iii) among urodelans, TH-involvement in skull development changes from a minimum in basal salamanders (Hynobiidae) to the most pronounced in derived ones (Salamandridae and Plethodontidae). Given the increasing regulatory function of THs in urodelan evolution, we hypothesized a stronger involvement of THs in the control of skeletogenesis in anurans with their most complex and dramatic metamorphosis among all amphibians. Our experimental study of skeletal development in the hypo- and hyperthyroid yellow-bellied toad (Bombina variegata: Bombinatoridae) supports the greater involvement of THs in the mediation of all stages of anuran cranial and postcranial bones formation. Similar to urodelans, B. variegata displays enhancing TH involvement in the development of cranial bones that arise during larval ontogeny: while the hormonal impact on early larval ossifications is minimal, the skull bones forming during metamorphosis are strictly TH-inducible. However, in contrast to urodelans, all cranial bones, including the earliest to form, are TH-dependent in B. variegata; moreover, the development of all elements of the axial and limb skeleton is affected by THs. The more accentuated hormonal control of skeletogenesis in B. variegata demonstrates the advanced regulatory and inductive function of THs in the orchestration of anuran metamorphosis. Based on these findings, we discuss (i) changes in THs function in amphibian evolution and (ii) the role of THs in the evolution of life histories in amphibians.

scholarly journals Ancestral form and function of larval feeding structures are retained during development of non-planktotrophic gastropods

2020 ◽  
Vol 52 ◽  
Author(s):  
Rachel Collin ◽  
Caitlin M. Shishido ◽  
Anabell J. Cornejo ◽  
Maryna P. Lesoway
Keyword(s):  
Marine Invertebrates ◽  
The Body ◽  
Larval Feeding ◽  
Complex Structures ◽  
Video Footage ◽  
Form And Function ◽  
Body Sizes ◽  
Planktotrophic Larvae ◽  
Mode Of Development ◽  
And Function

Mode of development (MOD) is a key feature that influences the rate and direction of evolution of marine invertebrates. Although many groups include species with different MODs, the evolutionary loss of feeding larvae is thought to be irreversible as the complex structures used for larval feeding and swimming are lost, reduced, or modified in many species lacking feeding larvae. This view is largely based on observations of echinoderms. Phylogenetic analysis suggests that feeding larvae have been re-gained in at least one species of calyptraeid gastropod. Further, its sister species has retained the velum, the structure used for larval feeding and swimming. Here, we document velar morphology and function in calyptraeids with 4 different MODs. Embryos of Crepidula navicella, Crepidula atrasolea, Bostrycapulus aculeatus, Bostrycapulus odites, Bostrycapulus urraca, Crepipatella dilatata, Crepipatella occulta, Crucibulum quiriquinae and Crepidula coquimbensis all hatch as crawling juveniles, yet only Crepidula coquimbensis does not make a well-formed velum during intracapsular development. The velar dimensions of 6 species with non-planktotrophic development were similar to those of planktotrophic species, while the body sizes were significantly larger. All of the species studied were able to capture and ingest particles from suspension, but several non-planktotrophic species may ingest captured particles only occasionally. Video footage suggests that some species with adelphophagic direct development capture but frequently fail to ingest particles compared to species with the other MODs. Together these lines of evidence show that, among calyptraeids at least, species that lack planktotrophic larvae often retain the structures and functions necessary to successfully capture and ingest particles, reducing the barriers to the re-evolution of planktotrophy.

scholarly journals Linking hunting weaponry to attack strategies in sailfish and striped marlin

2020 ◽  
Vol 287 (1918) ◽  
pp. 20192228 ◽  
Author(s):  
M. J. Hansen ◽  
S. Krause ◽  
M. Breuker ◽  
R. H. J. M. Kurvers ◽  
F. Dhellemmes ◽  
...  
Keyword(s):  
Feeding Behaviour ◽  
High Speed ◽  
Feeding Strategies ◽  
Prey Choice ◽  
Micro Ct ◽  
Istiophorus Platypterus ◽  
Morphological Differences ◽  
Feeding Adaptations ◽  
Capture Rates

Linking morphological differences in foraging adaptations to prey choice and feeding strategies has provided major evolutionary insights across taxa. Here, we combine behavioural and morphological approaches to explore and compare the role of the rostrum (bill) and micro-teeth in the feeding behaviour of sailfish ( Istiophorus platypterus ) and striped marlin ( Kajikia audax ) when attacking schooling sardine prey. Behavioural results from high-speed videos showed that sailfish and striped marlin both regularly made rostrum contact with prey but displayed distinct strategies. Marlin used high-speed dashes, breaking schools apart, often contacting prey incidentally or tapping at isolated prey with their rostra; while sailfish used their rostra more frequently and tended to use a slower, less disruptive approach with more horizontal rostral slashes on cohesive prey schools. Capture success per attack was similar between species, but striped marlin had higher capture rates per minute. The rostra of both species are covered with micro-teeth, and micro-CT imaging showed that species did not differ in average micro-tooth length, but sailfish had a higher density of micro-teeth on the dorsal and ventral sides of their rostra and a higher amount of micro-teeth regrowth, suggesting a greater amount of rostrum use is associated with more investment in micro-teeth. Our analysis shows that the rostra of billfish are used in distinct ways and we discuss our results in the broader context of relationships between morphological and behavioural feeding adaptations across species.

scholarly journals Discovery of digestive enzymes in carnivorous plants with focus on proteases

2018 ◽  
Author(s):  
Rishiesvari Ravee ◽  
Faris ‘Imadi Mohd Salleh ◽  
Hoe-Han Goh
Keyword(s):  
Digestive Enzymes ◽  
Recent Progress ◽  
Digestive Enzyme ◽  
Industrial Applications ◽  
Carnivorous Plants ◽  
Pitcher Plants ◽  
Enzyme Discovery ◽  
Plant Proteases ◽  
Recombinant Technology

Background. Carnivorous plants have been fascinating researchers with their unique characters and bioinspired applications. These include medicinal trait of some carnivorous plants with potentials for pharmaceutical industry. Methods. This review will cover recent progress based on current studies on digestive enzymes secreted by different genera of carnivorous plants: Drosera (sundews), Dionaea (Venus flytrap), Nepenthes (tropical pitcher plants), Sarracenia (North American pitcher plants), Cephalotus (Australian pitcher plants), Genlisea (corkscrew plants), and Utricularia (bladderworts). Results. Since the discovery of secreted protease nepenthesin in Nepenthes pitcher, digestive enzymes from carnivorous plants have been the focus of many studies. Recent genomics approaches have accelerated digestive enzyme discovery. Furthermore, the advancement in recombinant technology and protein purification helped in the identification and characterisation of enzymes in carnivorous plants. Discussion. These different aspects will be described and discussed in this review with focus on the role of secreted plant proteases and their potential industrial applications.

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