Sperm Nuclear Basic Proteins of Marine Invertebrates

Author(s):  
Anna Török ◽  
Sebastian G. Gornik
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


Planta Medica ◽  
2013 ◽  
Vol 79 (10) ◽  
Author(s):  
DTA Youssef ◽  
LA Shaala ◽  
F Al-Jamali ◽  
E Schmidt

2014 ◽  
Vol 41 (1) ◽  
pp. 1-16 ◽  
Author(s):  
B. J. Gill

In December 1884 Charles Francis Adams (1857–1893) left Illinois, USA, by train for San Francisco and crossed the Pacific by ship to work as taxidermist at Auckland Museum, New Zealand, until February 1887. He then went to Borneo via several New Zealand ports, Melbourne and Batavia (Jakarta). This paper concerns a diary by Adams that gives a daily account of his trip to Auckland and the first six months of his employment (from January to July 1885). In this period Adams set up a workshop and diligently prepared specimens (at least 124 birds, fish, reptiles and marine invertebrates). The diary continues with three reports of trips Adams made from Auckland to Cuvier Island (November 1886), Karewa Island (December 1886) and White Island (date not stated), which are important early descriptive accounts of these small offshore islands. Events after leaving Auckland are covered discontinuously and the diary ends with part of the ship's passage through the Dutch East Indies (Indonesia), apparently in April 1887. Adams's diary is important in giving a detailed account of a taxidermist's working life, and in helping to document the early years of Auckland Museum's occupation of the Princes Street building.


2018 ◽  
Vol 25 (20) ◽  
pp. 2292-2303 ◽  
Author(s):  
Negar Talaei Zanjani ◽  
Monica Miranda Saksena ◽  
Fariba Dehghani ◽  
Anthony L. Cunningham

Hemocyanins are large and versatile glycoproteins performing various immunological and biological functions in many marine invertebrates including arthropods and molluscs. This review discusses the various pharmacological applications of mollusc hemocyanin such as antiviral activity, immunostimulatory and anticancer properties that have been reported in the literature between the years 2000 and 2016. Emphasis is placed on a better mechanistic understanding of hemocyanin as a therapeutic agent. Elucidation of the mechanism of action is essential to improve the clinical efficacy and for a better understanding of some endogenous immunological functions of this complex glycoprotein.


A commonality among oceanic life cycles is a process known as settlement, where dispersing propagules transition to the sea floor. For many marine invertebrates, this transition is irreversible, and therefore involves a crucial decision-making process through which larvae evaluate their juvenile habitat-to-be. In this chapter, we consider aspects of the external environment that could influence successful settlement. Specifically, we discuss water flow across scales, and how larvae can engage behaviors to influence where ocean currents take them, and enhance the likelihood of their being carried toward suitable settlement locations. Next, we consider what senses larvae utilize to evaluate their external environment and properly time such behavioral modifications, and settlement generally. We hypothesize that larvae integrate these various external cues in a hierarchical fashion, with differing arrangements being employed across ontogeny and among species. We conclude with a brief discussion of the future promises of larval biology, ecology, and evolution.


Larvae of many marine invertebrates must capture and ingest particulate food in order to develop to metamorphosis. These larvae use only a few physical processes to capture particles, but implement these processes using diverse morphologies and behaviors. Detailed understanding of larval feeding mechanism permits investigators to make predictions about feeding performance, including the size spectrum of particles larvae can capture and the rates at which they can capture them. In nature, larvae are immersed in complex mixtures of edible particles of varying size, density, flavor, and nutritional quality, as well as many particles that are too large to ingest. Concentrations of all of these components vary on fine temporal and spatial scales. Mechanistic models linking larval feeding mechanism to performance can be combined with data on food availability in nature and integrated into broader bioenergetics models to yield increased understanding of the biology of larvae in complex natural habitats.


Author(s):  
Judith Fuchs

This chapter describes the taxonomy of Phoronida, a small group of exclusively marine invertebrates found in most of the world's oceans from the intertidal zone to about 400 metres depth. Phoronids are meroplanktonic with a planktonic larval stage usually less than 2 mm in length and a benthic adult whose length ranges from a few cm up to 50 cm. The chapter covers their life cycle, ecology, and general morphology. It includes a section that indicates the systematic placement of the taxon described within the tree of life, and lists the key marine representative illustrated in the chapter (usually to genus or family level). This section also provides information on the taxonomic authorities responsible for the classification adopted, recent changes which might have occurred, and lists relevant taxonomic sources.


Author(s):  
Andrew Clarke

The extreme meteorological surface air temperatures recorded to date are –89.2 oC in Antarctica, and 56.7 oC in Death Valley, California. Ground temperatures can be higher or lower than these air temperatures. The bulk of oceanic water is cold (< 4 oC) and thermally stable. Whilst data on limits to survival attract considerable attention, the thermal limits to completion of the life cycle (which define the limits to life) are much less well known. Currently identified upper thermal limits for growth are 122 oC for archaeans, 100 oC for bacteria and ~60 oC for unicellular eukaryotes. No unicells appear to grow below –20 oC, a limit that is probably set by dehydration-linked vitrification of the cell interior. The lower thermal limits for survival in multicellular organisms in the natural world extend to at least –70 oC. However in all cases known to date, completion of the life cycle requires summer warmth and the lowest temperature for completion of a multicellular eukaryote life cycle appears to be ~0 oC for invertebrates in glacial meltwater and ~–2 oC for marine invertebrates and fish living on the continental shelves around Antarctica.


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