The physiology of Crustacea

Osmotic regulation in crustaceans

Variation in the appearance of guppy color patterns to guppies and their predators under different visual conditions.

It is ten years since the last review on Osmotic and Ionic Regulation in Animals appeared in the Annual Review of Physiology (1). Since that time the field has been reviewed by Shaw (2), by Potts & Parry (3), and by Prosser & Brown (4 ) . In addition a number of the more important groups of animals have been reviewed in the Academic Press series of books on the physiology of selected groups. In the light of these later works this review will be confined largely to the more recent papers on the subject. It is difficult to define exactly the scope of this subject as it overlaps with the field of renal physiology, which is reviewed almost annually in this periodical, and also with transport through biological membranes re­ viewed by Rothstein ( 5) in the present volume. The limits covered in this review are defined in the last resort by the personal prejudices of the writ­ er, but the main emphasis will be placed on the regulation of the salt and water balance of the whole animal. Active transport and excretory systems will be discussed from this point of view. The material for this review has been arranged largely in a systematic fashion for the convenience of readers interested in particular groups. An exception has been made in the discussion of the fine structure of salt­ transporting tissues where the number of papers is limited and interphylet­ ic comparisons are more profitable.

Osmotic and ionic regulation.

Geographic variation in morphometry has been used todiscriminate local forms of fish for over a century. The historical development of stock identificationmethods has paralleled the advancement of morphometrictechniques. The earliest analyses of morphometricvariables for stock identification were univariatecomparisons, but were soon followed by bivariateanalyses of relative growth to detect ontogeneticchanges and geographic variation among fishstocks. As the field of multivariatemorphometrics flourished, a suite of multivariatemethods was applied to quantify variation in growthand form among stocks. More recent advances have beenfacilitated by image processing techniques, morecomprehensive and precise data collection, moreefficient quantification of shape, and new analyticaltools. Many benchmark case studies and critiquesoffer guidelines for sampling morphometrics andinterpreting multivariate analyses for exploratorystock identification, stock discrimination, and stockdelineation. As examples of morphometric stockidentification based on life history differences,allometric patterns of crustacean secondary sexcharacters have been used to detect geographicvariation in size at maturity, and morphometriccorrelates to smoltification have been used todiscriminate salmon from different rivers. Morphometric analysis provides a powerful complementto genetic and environmental stock identificationapproaches. The challenge for the future ofmorphometric stock identification is to develop aconsensus on biological interpretations of geometricanalyses, similar to the conventional interpretationsof size and shape from traditional multivariatemorphometrics.

Advances in morphometric identification of fishery stocks

Osmotic and ionic regulation in the Crustacea is mostly accomplished by the multifunctional gills, together with the excretory organs. In addition to their role in gas exchange, the gills constitute organs of active, transepithelial, ion transport, an activity of major importance that underlies many essential physiological functions like osmoregulation, calcium homeostasis, ammonium excretion and extracellular pH regulation. This review focuses on structure-function relationships in crustacean gills and excretory effectors, from the organ to molecular levels of organization. We address the diversity of structural architectures encountered in different crustacean gill types, and in constituent cell types, before examining the physiological mechanisms of Na(+), Cl(-), Ca(2+) and NH(4)(+) transport, and of acid-base equivalents, based on findings obtained over the last two decades employing advanced techniques. The antennal and maxillary glands constitute the principal crustacean excretory organs, which have received less attention in functional studies. We examine the diversity present in antennal and maxillary gland architecture, highlighting the structural similarities between both organ types, and we analyze the functions ascribed to each glandular segment. Emphasis is given to volume and osmoregulatory functions, capacity to produce dilute urine in freshwater crustaceans, and the effect of acclimation salinity on urine volume and composition. The microanatomy and diversity of function ascribed to gills and excretory organs are appraised from an evolutionary perspective, and suggestions made as to future avenues of investigation that may elucidate evolutionary and adaptive trends underpinning the invasion and exploitation of novel habitats.

The physiology of Crustacea

Citations

Osmotic regulation in crustaceans

Variation in the appearance of guppy color patterns to guppies and their predators under different visual conditions.

Osmotic and ionic regulation.

Advances in morphometric identification of fishery stocks

A structure-function analysis of ion transport in crustacean gills and excretory organs.

Related Papers (5)

The Biology of Crustacea

Chapter 15 – molting and its control

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Osmotic and ionic regulation

Comparative animal physiology