Collodaria

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Collodaria
Radiolaria (Challenger) Plate 008.jpg
Collosphærida as illustrated by Adolf Giltsch in Haeckel's Report on the Radiolaria collected by H.M.S. Challenger during the years 1873-1876
Scientific classification Red Pencil Icon.png
Kingdom: Chromista
Phylum: Retaria
Class: Polycystina
Order: Collodaria
Haeckel, 1881

Collodaria is a unicellular order (organisms within the order are called Collodarians) under the phylum Radiozoa (or Radiolaria) and the infrakingdom Rhizaria. Like most of the Radiolaria taxonomy, Collodaria was first described by Ernst Haeckel, a German scholar who published three volumes of manuscript describing the extensive samples of Radiolaria collected by the voyage of HMS Challenger. Recent molecular phylogenetic studies concluded that there are Collodaria contains three families, Sphaerozodae, Collosphaeridae, and Collophidilidae.

Contents

Story and origin

Ernst Haeckel is the main contributor to species description in the phylum Radiolaria, which contains the order Collodaria. [1] Members of Collodaria were first described in 1862. [2] In 1881, Collodaria was defined by Haeckel in 1881 as “Spumellaria without latticed shell.” [3]

The story behind this order involved the historic voyage of HMS Challenger. As recorded in the manuscript of "Report on the Scientific Results of the Voyage of H.M.S. Challenger during the years 1873-1876," HMS Challenger embarked from Portsmouth, England in December 1872. [4] On board this military vessel that had auxiliary steam power were physicists, chemists and biologists led by Captain Wyville Thomson, collaborating in an interdisciplinary venture to discover the diversity of life. With guns removed from the ships and replaced with long sampling rope, wire, thermometers, bottom samplers and water bottles, “naturalists” on board collected samples of marine organisms and fossils throughout the ocean waters. After the death of Wyville Thomson, his successor John Murray supervised the publication and research of collected data from the voyage at which point samples of radiolarians were passed onto Haeckel who was already a professor at the University of Jena, Germany. In the editorial notes of the report, Murray stated that Haeckel's "Report on the Radiolaria collected by H.M.S. Challenger" represents Haeckel's ten years' devotion. [5] In Haeckel's report, all existing knowledge on Radiolaria was recorded, and older species and fossils were redescribed into three volumes.

It is indisputable that Haeckel's contribution built the foundation of morphological knowledge in Radiolaria and its orders including Collodaria. However, research in recent years has found major discrepancies between molecular phylogenetic trees and Haeckel's morphology-based phylogenetic trees. Mistakes in phylogeny were likely made when Haeckel characterized different lifecycles as two species. [6] [7] [8] Some of these discrepancies are addressed in the summary of the most recent research on the phylogenetic relationships within Collodaria found in following section.

Habitat and ecology

Collodarians are found throughout the oceans but high populations of Collodarians aggregate in calm and oligotrophic surface waters. [9] Biard et al. (2015) quoted high densities of Collodarian colonies has been reported in the Gulf of Aden and in the North Pacific Ocean. [7] The diverse distribution and abundance of Collodaria suggest its significance in ecology and the biogeochemical pathways of the oceans. [10] Collodarians are mixotrophs involved in different trophic levels within the ocean food webs since they can actively prey on a variety of organisms including copepods, ciliates, phytoplankton, and bacteria. [6] Collodarians can participate in carbon fixation as most species have acquired intracellular microalgae symbionts (Hollande and Enjumet 1953). Dinoflagellate Brandotodium nutricula is a common endosymbiont of Collodarians. [7]

Description of morphological diversity

Aside from the common morphology shared by radiolarians such as the axopodia, nucleus and metabolic organelles in internal endoplasm and the separation of external and internal endoplasm by the central capsule, most species of Collodaria form colonies in nature. [10] Anderson et al. (1999) observed that the colony shapes are not species-specific. Colonial Collodarian cells can agglutinate in a gelatinous matrix that can be as small as a few mm to as large as 3 m in length. [7] There have been observations of large solitary species (up to a few mm). Three types of skeleton are observed in Collodaria: some species create shell-like skeleton around the central capsule, others form silica spicules or have no mineral structures. The shape of central capsules and density of cytoplasmic vacuoles can vary among species and may serve as a distinguishing taxonomic character such as the separation of the genera Collophidium and Collozoum within the family of Sphaerozoidae. [10]

Fossil records

The siliceous shells of Collodaria are often preserved in sediment for millions of years. Micropaleontologists have utilized the fossil records of Collodaria to describe extinct species and the evolution of extant species through time using various notable features on the skeleton such as the size, number of radiate spines, and the presence of appendages. [7] It was estimated that the lineage of Radiolarians, the ancestors of Collodaria, arose in early Paleozoic era. [11]

Phylogenetic relationships

Sister orders of Collodaria

In the Haeckel's work, Collodaria was named the first order of Radiolaria, and defined as “Spumellaria without latticed shell.” This definition of Collodaria was further expanded to include organisms that either completely lack the skeleton or have numerous spicules that loosely scatter throughout the calymma around the central capsule. [10] In recent literature, the definition of Collodaria has been altered with molecular phylogenetic characteristics. [7] In Haeckel's phylogeny, the second order in Radiolaria, Sphaerellaria, includes all Radiolaria with any trace of latticed or fenestrated shell. [3] In the last decade, Radiolarians are reclassified in five taxonomic orders as characterized by the composition and morphology of the mineral skeletons which include Acantharia with strontium sulphate skeleton, Taxopodida with silica skeleton, Collodaria, Nassellaria and Spumellaria with polycystine silica skeleton. [8] Hence, in the current classification Collodaria now has four sister orders instead of having one sister order as in Haeckel's original tree. Collodaria, Nassellaria and Spumellaria are sometimes called the Polycystines for their shared skeleton composition character. [10]

Families within Collodaria

Because most Collodaria species are colonial while others appear to be solitary, Collodaria was once divided into three families based on their lifestyle: Thalassicollidae, Collosphaeridae, and Sphaerozoidea. Thalassicollidae is characterized by solitary cells without a silica skeleton. [7] [10] Collosphaeridae and Sphaerozoidea are distinguished from each other based on the morphology of the silica skeleton. In 2012, Ishitan and colleagues performed a phylogenetic analysis and found four novel Collodaria sequences which supported the division of Collodaria into four families: Thalassicollidae, Collozoidae, Collosphaeridae, and Collophidae. [10] However, a recent study published by Baird et al. (2015) refuted this division. In a molecular phylogeny constructed by nuclear ribosomal DNA small and large subunits of Collodaria, the skeleton-lacking and spicule-bearing Sphaerozodae, and its sister clades the skeleton-bearing Collosphaeridae and skeleton-lacking Collophidilidae were found to be monophyletic but Thalassicollidae was found to be paraphyletic. [7] To confirm findings, molecular analyses and morphologies of members were observed. Contrary to previous beliefs, species in Collosphaeridae include solitary, colonial species, skeleton-lacking and skeleton-bearing species. Intraspecific variability in silicified skeletal structures was also observed which emphasized the uncertainty in morphology-based classification.

Related Research Articles

<span class="mw-page-title-main">Acantharea</span> Class of single-celled organisms

The Acantharea (Acantharia) are a group of radiolarian protozoa, distinguished mainly by their strontium sulfate skeletons. Acantharians are heterotrophic marine microplankton that range in size from about 200 microns in diameter up to several millimeters. Some acantharians have photosynthetic endosymbionts and hence are considered mixotrophs.

<span class="mw-page-title-main">Radiolaria</span> Phylum of single-celled organisms

The Radiolaria, also called Radiozoa, are protozoa of diameter 0.1–0.2 mm that produce intricate mineral skeletons, typically with a central capsule dividing the cell into the inner and outer portions of endoplasm and ectoplasm. The elaborate mineral skeleton is usually made of silica. They are found as zooplankton throughout the global ocean. As zooplankton, radiolarians are primarily heterotrophic, but many have photosynthetic endosymbionts and are, therefore, considered mixotrophs. The skeletal remains of some types of radiolarians make up a large part of the cover of the ocean floor as siliceous ooze. Due to their rapid change as species and intricate skeletons, radiolarians represent an important diagnostic fossil found from the Cambrian onwards.

<span class="mw-page-title-main">Polycystine</span> Class of single-celled organisms

The polycystines are a group of radiolarians. They include the vast majority of the fossil radiolaria, as their skeletons are abundant in marine sediments, making them one of the most common groups of microfossils. These skeletons are composed of opaline silica. In some it takes the form of relatively simple spicules, but in others it forms more elaborate lattices, such as concentric spheres with radial spines or sequences of conical chambers. Two of the orders belonging to this group are the radially-symmetrical Spumellaria, dating back to the late Cambrian period, and the bilaterally-symmetrical Nasselaria, whose origin is placed within the lower Devonian.

<span class="mw-page-title-main">Phaeodarea</span> Class of protists

Phaeodarea, or Phaeodaria, is a group of amoeboid cercozoan organisms. They are traditionally considered radiolarians, but in molecular trees do not appear to be close relatives of the other groups, and are instead placed among the Cercozoa. They are distinguished by the structure of their central capsule and by the presence of a phaeodium, an aggregate of waste particles within the cell.

<span class="mw-page-title-main">Microfossil</span> Fossil that requires the use of a microscope to see it

A microfossil is a fossil that is generally between 0.001 mm and 1 mm in size, the visual study of which requires the use of light or electron microscopy. A fossil which can be studied with the naked eye or low-powered magnification, such as a hand lens, is referred to as a macrofossil.

<span class="mw-page-title-main">Demosponge</span> Class of sponges

Demosponges (Demospongiae) are the most diverse class in the phylum Porifera. They include 76.2% of all species of sponges with nearly 8,800 species worldwide. They are sponges with a soft body that covers a hard, often massive skeleton made of calcium carbonate, either aragonite or calcite. They are predominantly leuconoid in structure. Their "skeletons" are made of spicules consisting of fibers of the protein spongin, the mineral silica, or both. Where spicules of silica are present, they have a different shape from those in the otherwise similar glass sponges. Some species, in particular from the Antarctic, obtain the silica for spicule building from the ingestion of siliceous diatoms.

<span class="mw-page-title-main">Spumellaria</span> Order of single-celled organisms

Spumellaria is an order of radiolarians in the class Polycystinea. They are ameboid protists appearing in abundance in the world's oceans, possessing a radially-symmetrical silica (opal) skeleton that has ensured their preservation in fossil records. They belong among the oldest Polycystine organisms, dating back to the lower Cambrian. Historically, many concentric radiolarians have been included in the Spumellaria order based on the absence of the initial spicular system, an early-develop structure that, by its lacking, sets them apart from Entactinaria despite their similar morphology. Living exemplars of the order feed by catching prey, such as copepod nauplii or tintinnids, on the adhesive ends of their pseudopodia extending radially from their skeleton; however, some have been observed as mixotrophs living in symbiosis with various photosynthetic algal organisms such as dinoflagellates, cyanobacteria, prasinophytes or haptophytes, which may cause their distribution to center in the greatest abundance and diversity within trophical waters.

<span class="mw-page-title-main">Spongodiscidae</span> Family of single-celled organisms

Spongodiscidae is a family of radiolarians in the order Spumellaria. According to the original description by Ernst Haeckel, members of the family have a flat discoidal shell, in which a simple spherical central chamber is surrounded by an irregular spongy framework.

<span class="mw-page-title-main">Stylosphaeridae</span> Family of single-celled organisms

Stylosphaeridae is a family of radiolarians in the order Spumellaria. According to the original description by Ernst Haeckel, members of the family have a spherical central capsule within a fenestrated spherical siliceous shell, with two radial spines opposite in one axis. They are solitary. i.e. not associated in colonies.

<span class="mw-page-title-main">Nassellaria</span> Order of single-celled organisms

Nassellaria is an order of Rhizaria belonging to the class Radiolaria. The organisms of this order are characterized by a skeleton cross link with a cone or ring.

<i>Cenellipsis</i> Genus of single-celled organisms

Cenellipsis is a genus of radiolarians in the order Spumellaria. The genus is extant but there are also fossil species.

<span class="mw-page-title-main">Phaeocystida</span> Group of single-celled organisms

Phaeocystida, also known as Phaeocystina, is a group of cercozoans in the class Phaeodarea. It was first described by Ernst Haeckel in 1887 and treated traditionally as a suborder, but later was raised to order level until Cavalier-Smith's classification lowered it again to suborder level. It belongs to the order Eodarida, characterised by simpler silica skeletons or a lack thereof.

Cornutanna is a genus of radiolarians in the order Nassellaria.

The genus Stylodictya belongs to a group of organisms called the Radiolaria. Radiolarians are amoeboid protists found as zooplankton in oceans around the world and are typically identified by their ornate skeletons.

<i>Collozoum</i> Genus of radiolaria

Collozoum is a radiolarian genus formerly reported in the subfamily Sphaerozoidae, now reported descending from the order Collodaria. The genus contains bioluminescent species. It is a genus of colonial radiolarians.

<i>Acrosphaera</i> Genus of radiolaria

Acrosphaera is a radiolarian genus in the Collosphaeridae. The genus contains bioluminescent species. It is a genus of colonial radiolarians.

Myxosphaera is a radiolarian genus in the Collosphaeridae. The genus may contain bioluminescent species. It is a genus of colonial radiolarians.

<span class="mw-page-title-main">Protist shell</span> Protective shell of a type of eukaryotic organism

Many protists have protective shells or tests, usually made from silica (glass) or calcium carbonate (chalk). Protists are mostly single-celled and microscopic. Their shells are often tough, mineralised forms that resist degradation, and can survive the death of the protist as a microfossil. Although protists are typically very small, they are ubiquitous. Their numbers are such that their shells play a huge part in the formation of ocean sediments and in the global cycling of elements and nutrients.

Vitalia Viktorovna Reshetnyak (Решетняк) (1925–2015) was a Soviet protozoologist and marine biologist, specialising in Radiolaria, Phaeodorea and Acantharea.

<span class="mw-page-title-main">Protists in the fossil record</span>

A protist is any eukaryotic organism that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor, the last eukaryotic common ancestor, the exclusion of other eukaryotes means that protists do not form a natural group, or clade. Therefore, some protists may be more closely related to animals, plants, or fungi than they are to other protists. However, like algae, invertebrates and protozoans, the grouping is used for convenience.

References

  1. ↑ "Studies from tohoku university yield new data on protistology [towards an integrative morpho-molecular classification of the Collodaria (polycystinea, radiolaria)]". Life Science Weekly (2754). 2015.
  2. ↑ Haeckel E (1862). Die Radiolarien (Rhizopoda Radiolaria). Berlin: Druck und Verlag von Georg Reimer. pp. xiv+ 572.
  3. 1 2 Haeckel E (1887). Report on the Radiolaria collected by HMS Challenger during the years 1873-1876. Report of the Voyage of HMS Challenger, Zoology. Vol. 18. Project Gutenberg. pp. i–clxxxviii.
  4. ↑ Thomson CW, Murray J, Nares GS, Thomson FT (1889). "Reports on the Scientific Results of the Voyage of H.M.S. "Challenger" during the years 1873-1876, under the Command of Capt Sir George Nares, R.N., F.R.S., and Capt F.T. Thomson, R.N.". Nature. 27 (682): 73–75. doi:10.1038/027073a0. S2CID   4075460.
  5. ↑ Krabberød AK, Bråte J, Dolven JK, Ose RF, Klaveness D, Kristensen T, Bjørklund KR, Shalchian-Tabrizi K (2011). "Radiolaria divided into Polycystina and Spasmaria in combined 18S and 28S rDNA phylogeny". PLOS ONE. 6 (8): e23526. Bibcode:2011PLoSO...623526K. doi: 10.1371/journal.pone.0023526 . PMC   3154480 . PMID   21853146.
  6. 1 2 Anderson OR, Swanberg NR (June 1981). "Skeletal morphogenesis in some living collosphaerid Radiolaria". Marine Micropaleontology. 6 (3): 385–96. Bibcode:1981MarMP...6..385A. doi:10.1016/0377-8398(81)90008-6.
  7. 1 2 3 4 5 6 7 8 Biard T, Pillet L, Decelle J, Poirier C, Suzuki N, Not F (July 2015). "Towards an Integrative Morpho-molecular Classification of the Collodaria (Polycystinea, Radiolaria)". Protist. 166 (3): 374–88. doi: 10.1016/j.protis.2015.05.002 . PMID   26092634.
  8. 1 2 Suzuki N, Aita Y (May 2011). "Radiolaria: achievements and unresolved issues: taxonomy and cytology". Plankton and Benthos Research. 6 (2): 69–91. doi: 10.3800/pbr.6.69 .
  9. ↑ Swanberg NR (1979). The ecology of colonial radiolarians: their colony morphology, trophic interactions and associations, behavior, distribution, and the photosynthesis of their symbionts (Ph.D. thesis). Massachusetts Institute of Technology and Woods Hole Oceanographic Institution.
  10. 1 2 3 4 5 6 7 Ishitani Y, Ujiié Y, de Vargas C, Not F, Takahashi K (2012). "Phylogenetic relationships and evolutionary patterns of the order Collodaria (Radiolaria)". PLOS ONE. 7 (5): e35775. Bibcode:2012PLoSO...735775I. doi: 10.1371/journal.pone.0035775 . PMC   3342292 . PMID   22567112.
  11. ↑ Hollande AC, Cachon-Enjumet M (1953). "Contribution à l'étude biologique des spaerocollides:(radiolaires collodaires et radiolaires polycyttaires) et de leurs parasites. Thalassicollidae, physematidae, thalassophysidae". Annales des Sciences Naturelles. 15: 99–183.
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