scholarly journals Evolution of Feeding Shapes Swimming Kinematics of Barnacle Naupliar Larvae: A Comparison between Trophic Modes

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
J Y Wong ◽  
B K K Chan ◽  
K Y K Chan
Keyword(s):  
Evolutionary Biology ◽  
High Speed ◽  
Morphological Changes ◽  
Marine Invertebrate ◽  
Ecological Functions ◽  
Micro Particle Image Velocimetry ◽  
Globular Body ◽  
Recovery Stroke ◽  
Induced Flow ◽  
Invertebrate Larvae

Synopsis A central goal in evolutionary biology is connecting morphological features with ecological functions. For marine invertebrate larvae, appendage movement determines locomotion, feeding, and predator avoidance ability. Barnacle larvae are morphologically diverse, and the morphology of non-feeding lecithotrophic nauplii are distinct from those that are planktotrophic. Lecithotrophic larvae have a more globular body shape and simplified appendages when compared with planktotrophs. However, little is known about whether and how such morphological changes affect kinematics, hydrodynamics, and ecological functions. Here, we compared the nauplii kinematics and hydrodynamics of a lecithotrophic Rhizocephalan species, Polyascus planus, against that of the planktotrophic nauplii of an intertidal barnacle, Tetraclita japonica. High-speed, micro-particle image velocimetry analysis showed that the Polyascus nauplii swam faster and had higher amplitude and more synchronous appendage beating than the Tetraclita nauplii. This fast swimming was accompanied by a faster attenuation of induced flow with distance, suggesting reduced predation risk. Tetraclita nauplii had more efficient per beat cycles with less backward displacement during the recovery stroke. This “anchoring effect” resulted from the anti-phase beating of appendages. This movement, together with a high-drag body form, likely helps direct the suction flow toward the ventral food capturing area. In sum, the tradeoff between swimming speed and predation risks may have been an important factor in the evolution of the observed larval forms.

Physiology of Larval Feeding

2018 ◽  
Keyword(s):  
Growth And Development ◽  
Marine Invertebrate ◽  
Larval Growth ◽  
Circulatory System ◽  
Future Research ◽  
Larval Feeding ◽  
Digestive Physiology ◽  
Larval Body ◽  
The Individual ◽  
Invertebrate Larvae

The functional properties of marine invertebrate larvae represent the sum of the physiological activities of the individual, the interdependence among cells making up the whole, and the correct positioning of cells within the larval body. This chapter examines physiological aspects of nutrient acquisition, digestion, assimilation, and distribution within invertebrate larvae from an organismic and comparative perspective. Growth and development of larvae obviously require the acquisition of “food.” Yet the mechanisms where particulate or dissolved organic materials are converted into biomass and promote development of larvae differ and are variably known among groups. Differences in the physiology of the digestive system (secreted enzymes, gut transit time, and assimilation) within and among feeding larvae suggest the possibility of an underappreciated plasticity of digestive physiology. How the ingestion of seawater by and the existence of a circulatory system within larvae contribute to larval growth and development represent important topics for future research.

Induced Flow Reciprocating Pump Theory Supported by New Performance Data

1972 ◽  
Vol 94 (4) ◽  
pp. 706-714 ◽  
Author(s):  
J. D. Burton ◽  
J. Lobo-Guerrero U.
Keyword(s):  
High Speed ◽  
Performance Data ◽  
Experimental Measurements ◽  
Long Time ◽  
Induced Flow ◽  
Hydraulic Accumulator ◽  
Reciprocating Pump

Reciprocating pumps have been employed in conjunction with air vessels and fluid accumulators for a long time in order to reduce maximum cylinder pressures and energy wastage in friction. More recently, diaphragm pumps, run at high speed, have been built utilizing a hydraulic accumulator or capacitance in conjunction with a hydraulic inductance, in order to greatly increase the flow output. Volumetric efficiencies of over 250 percent have been obtained. The present paper describes briefly this induced flow principle and then compares theoretical solutions with experimental measurements taken in the first commercially available pump of this type.

scholarly journals Bryostatin 1 induces differentiation of B-chronic lymphocytic leukemia cells

Blood ◽  
1989 ◽  
Vol 74 (5) ◽  
pp. 1747-1757 ◽  
Author(s):  
HG Drexler ◽  
SM Gignac ◽  
RA Jones ◽  
CS Scott ◽  
GR Pettit ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Rna Synthesis ◽  
Morphological Changes ◽  
Marine Invertebrate ◽  
Qualitative Difference ◽  
Calcium Ionophore ◽  
Lymphocytic Leukemia ◽  
Ionophore A23187 ◽  
Bryostatin 1 ◽  
Stimulatory Action

Abstract Peripheral blood cells from nine patients with B-chronic lymphocytic leukemia (B-CLL) were treated in vitro with bryostatin 1 (a macrocyclic lactone derived from a marine invertebrate). Like the phorbol ester 12- 0-tetradecanoyl-phorbol 13-acetate (TPA), bryostatin 1 activates protein kinase C (PKC), which plays a central role in the phosphatidylinositol signal transduction pathway. The effects of bryostatin 1 alone and in combination with TPA or with the calcium mobilizing ionophore A23187 were assessed by morphological appearance, cell adherence and aggregation, RNA and DNA synthesis, and immunoglobulin (Ig) production. While eight of nine B-CLL cultures remained proliferatively inert, bryostatin 1 could effectively trigger activation and differentiation of B-CLL cells in all cases as inferred by the induction of morphological changes, RNA synthesis, and monotypic Ig production. Addition of calcium ionophore A23187 to bryostatin 1- exposed cells resulted in significantly increased values for RNA synthesis and Ig production and in the acquisition of plasmacytoid morphology. Bryostatin 1 and the dual signal of bryostatin 1 plus A23187 mimicked the stimulatory action of TPA and the combination of TPA plus A23187, respectively. Overall, bryostatin 1 was less active than equivalent concentrations of TPA. This lesser efficacy may, however, reflect a quantitative rather than qualitative difference. Bryostatin 1 partially antagonized TPA-mediated effects on B-CLL cells suggesting different modes of action by the two activators. These studies indicate that bryostatin 1 has effective differentiation- inducing properties on B-CLL cells that can differentiation-inducing properties on B-CLL cells that can be accentuated by a calcium ionophore.

The induction of metamorphosis of marine invertebrate larvae: stimulus and response

1983 ◽  
Vol 61 (8) ◽  
pp. 1701-1719 ◽  
Author(s):  
Robert D. Burke
Keyword(s):  
Direct Evidence ◽  
Marine Invertebrate ◽  
Behavioral Model ◽  
Environmental Cues ◽  
Sensory Receptors ◽  
Response Model ◽  
Endocrine Control ◽  
Stimulus Response ◽  
Invertebrate Larvae ◽  
Induction Of Metamorphosis

The induction of metamorphosis by environmentally derived cues is reviewed in barnacles, molluscs, hydroids, echinoids, and ascidians in the context of the neurological and behavioral model of stimulus and response. The model proposes that cues associated with preferred juvenile or adult habitats are the stimuli. Stimuli are received by receptors that communicate with the effectors of metamorphosis, larval and adult tissues. The response is a combination of morphogenetic, histolytic, and histogenic processes. Receptors in all five taxa are assumed to be superficial sensory receptors, though there is no direct evidence for their involvement in the perception of cues. Although the induction of metamorphosis by environmental cues in all five taxa fits well within a stimulus–response model, there is currently only circumstantial evidence for neural or endocrine control of metamorphosis.

Size-Specific Predation on Marine Invertebrate Larvae

2008 ◽  
Vol 214 (1) ◽  
pp. 42-49 ◽  
Author(s):  
Jonathan D. Allen
Keyword(s):  
Marine Invertebrate ◽  
Invertebrate Larvae

scholarly journals Deep phenotyping, including quantitative ciliary beating parameters, and extensive genotyping in primary ciliary dyskinesia

2019 ◽  
Vol 57 (4) ◽  
pp. 237-244 ◽  
Author(s):  
Sylvain Blanchon ◽  
Marie Legendre ◽  
Mathieu Bottier ◽  
Aline Tamalet ◽  
Guy Montantin ◽  
...  
Keyword(s):  
Primary Ciliary Dyskinesia ◽  
High Speed ◽  
Genetic Disorder ◽  
Beat Frequency ◽  
Ciliary Beat Frequency ◽  
Central Complex ◽  
Ciliary Beating ◽  
Recovery Stroke ◽  
Biallelic Mutations ◽  
Ciliary Dyskinesia

BackgroundPrimary ciliary dyskinesia (PCD) is a rare genetic disorder resulting in abnormal ciliary motility/structure, extremely heterogeneous at genetic and ultrastructural levels. We aimed, in light of extensive genotyping, to identify specific and quantitative ciliary beating anomalies, according to the ultrastructural phenotype.MethodsWe prospectively included 75 patients with PCD exhibiting the main five ultrastructural phenotypes (n=15/group), screened all corresponding PCD genes and measured quantitative beating parameters by high-speed video-microscopy (HSV).ResultsSixty-eight (91%) patients carried biallelic mutations. Combined outer/inner dynein arms (ODA/IDA) defect induces total ciliary immotility, regardless of the gene involved. ODA defect induces a residual beating with dramatically low ciliary beat frequency (CBF) related to increased recovery stroke and pause durations, especially in case of DNAI1 mutations. IDA defect with microtubular disorganisation induces a low percentage of beating cilia with decreased beating angle and, in case of CCDC39 mutations, a relatively conserved mean CBF with a high maximal CBF. Central complex defect induces nearly normal beating parameters, regardless of the gene involved, and a gyrating motion in a minority of ciliated edges, especially in case of RSPH1 mutations. PCD with normal ultrastructure exhibits heterogeneous HSV values, but mostly an increased CBF with an extremely high maximal CBF.ConclusionQuantitative HSV analysis in PCD objectives beating anomalies associated with specific ciliary ultrastructures and genotypes. It represents a promising approach to guide the molecular analyses towards the best candidate gene(s) to be analysed or to assess the pathogenicity of the numerous sequence variants identified by next-generation-sequencing.

The Distribution of Settled Larvae of the Bryozoans Alcyonidium Hirsutum (Fleming) and Alcyonidium Polyoum (Hassall) on Fucus Serratus L.

1974 ◽  
Vol 54 (3) ◽  
pp. 665-676 ◽  
Author(s):  
P. J. Hayward ◽  
Paul H. Harvey
Keyword(s):  
Aquatic Invertebrates ◽  
Marine Invertebrate ◽  
Substrate Selection ◽  
Sessile Invertebrates ◽  
Fucus Serratus ◽  
The Subject ◽  
Invertebrate Larvae ◽  
Experi Mental Result ◽  
Selection Of

The spatial settlement of marine invertebrate larvae is not a random process. The distribution of the adults of a particular species is influenced by the behavioural responses of the animal to a range of environmental stimuli which, in the case of many sessile invertebrates, result in the display of clear substrate selection. The role of habitat selection in determining the distribution of aquatic invertebrates has been the subject of a review by Meadows & Campbell (1972). The selection of algal substrata by the larvae of various intertidal species of Bryozoa has been demonstrated by Ryland (1959); among these, the ctenostomatous bryozoans Alcyonidium hirsutum and A. polyoum were shown to exhibit a strong preference for fronds of the alga Fucus serratus, an experi-mental result which accorded well with the distribution of the two species on the shore (Ryland, 1962).

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