Tiny Marine Research Articles

FISH: THE GUTS OF THE CARBON CYCLE

![Figure][1] Traditionally, oceanic calcification is credited to tiny marine plankton, mostly coccolithophores and foraminifera. These plankton combine seawater calcium with bicarbonate to form calcium carbonate, carbon dioxide and water, via the inorganic marine carbon cycle. When plankton

Optimization of DNA extraction from a single living ciliate for stable and repetitive PCR amplification

Ciliates are undoubtedly one of the most diverse protozoans that play a significant role in ecology. However, molecular examination, based on comparing the DNA sequences, has been done on a limited number of the species. Because most ciliates are uncultivable and their population sizes are often too small, it is usually difficult to obtain sufficient genomic DNA required for PCR based experiments. In the present study, we evaluated the effectiveness of four commercial DNA extraction procedures that extract high quality genomic DNA from a single ciliate cell. It was discovered that RED Extract‐N‐AmpTM PCR kit is the best method for removing PCR‐inhibiting substances and minimizing DNA loss during purification. This method can also amplify more than 25 reactions of PCR. In addition, this technique was applied to single cells of 19 species belonged to 7 orders under 5 classes that isolated from mixed natural populations. Their small subunit ribosomal DNA (SSU rDNA) was successfully amplified. In summary, we developed a simple technique for the high‐yield extraction of purified DNA from a single ciliate cell that may be more useful for rare ciliates, such as tiny and uncultivable marine microbes.

THE ALGAE BLOOMS PHENOMENON - A MATHEMATICAL MODEL

Pollution with sources from towns and industrial centres affect considerable the ecosystem waters. An accumulation of nutrients favourable to the growth of certain tiny marine organisms called phytoplankton stimulates their rapid reproduction in the water. These plankton blooms appear as patches on the surface of the water. The consequence of this process is the diminishing of the amount of oxygen from water (in the process of decompose the algae), the decease of aquatic animal and the multiply of bacterium, which produce the hydrogen sulphide. In this paper this phenomenon was analyzed using mathematical modelling. It is assumed that the dynamics of the algae blooms is governed by a Cauchy problem for system of two nonlinear ordinary equations with three parameters. The bifurcation diagram for the liniarized case is studied.

Squirt alert: A tiny marine alien is emerging as a coastal grinch

Science NewsVolume 168, Issue 26-27 p. 411-413 Feature Squirt alert: A tiny marine alien is emerging as a coastal grinch Janet Raloff, Janet RaloffSearch for more papers by this author Janet Raloff, Janet RaloffSearch for more papers by this author First published: 25 September 2009 https://doi.org/10.2307/4016903AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume168, Issue26-2724 ‐ 31 December 2005Pages 411-413 RelatedInformation

My favorite animal, Trichoplax adhaerens

Trichoplax adhaerens is more simply organized than any other living metazoan. This tiny marine animal looks like a irregular "hairy plate" ("tricho plax") with a simple upper and lower epithelium and some loose cells in between. After its original description by F.E. Schulze 1883, it attracted particular attention as a potential candidate representing the basic and ancestral state of metazoan organization. The lack of any kind of symmetry, organs, nerve cells, muscle cells, basal lamina and extracellular matrix originally left little doubt about the basal position of T. adhaerens. Nevertheless, the interest of zoologists and evolutionary biologists suddenly vanished for more than half a century when Trichoplax was claimed to be an aberrant hydrozoan planula larva. Recently, Trichoplax has been rediscovered as a key species for unraveling early metazoan evolution. For example, research on regulatory genes and whole genome sequencing promise insights into the genetics underlying the origin and development of basal metazoan phyla. Trichoplax offers unique potential for understanding the minimal requirements of metazoan animal organization.

Placozoa are not derived cnidarians: evidence from molecular morphology.

The phylum Placozoa is represented by a single known species, Trichoplax adhaerens, a tiny marine organism that represents the most simple metazoan bauplan. Because of the latter, placozoans were originally considered the most basal metazoan phylum. A misinterpretation of the life cycle at the turn of the century and some more recent molecular phylogenetic analyses have placed Trichoplax as a derived species within the Cnidaria. The latter hypothesis assumes that the primitive organization of the Placozoa is the result of secondary reduction. Here we compare the molecular morphology of the predicted 16S rDNA structure and the mitochondrial genome between Trichoplax and representatives of all four cnidarian classes. Trichoplax shares a circular mtDNA molecule as a plesiomorphy with all other metazoans except for the derived cnidarian classes Hydrozoa, Scyphozoa, and Cubozoa. The predicted secondary structure of the 16S rRNA molecule differs substantially between Trichoplax and cnidarians, particularly with respect to the number and length of stem and loop regions. The new molecular morphological characters provide compelling evidence that Trichoplax is not a derived (medusozoan) cnidarian. Furthermore, it was found that the mitochondrial genome in Cubozoa consists of four linear molecules instead of a single circular molecule or two linear molecules, suggesting that the cubozoans may represent the most derived cnidarian group.

Fine structure of the lateral eyes in the tiny marine Antarctic mite Halacarellus thomasi : an ultrastructural study

The lateral eyes of the tiny marine /-Vntarclic mite, Halacarellus iliomasi, consist of two entities in the same eye capsule. The oplical axes of the two eyes point in different directions and the two eyes are of different sizes- The larger of the two is covered by a circular lens of approximately 13 |im diameter, with considerably greater inner than outer convex curvature. The cover of the smaller eye consists of little else than a circular 10-).m'i-\vide transparent patch of cuticle. Both eyes have an everted retina with few (4-6) retinula cells, and their microvilli, which are oriented perpendicular to the light' path, have diameters of 55 nm. Screening pigments in the form of lipid-like, electron-opaque cell inclusions, measuring 1-2 um in size, are abundant on the proximal side of the retina. A small l-)im-thick muscle is in con­ tact with the eye capsule. On the basis of our structural data and comparisons with other mite species, we con­ clude that form, colour and polarization vision would play no role in the eye of /-/, ihouiasi. More likely, (he function of the eye is to monitor seasonal daylength changes to allow synchronization of reproductive activities.

Muscle cells in the tiny marine Antarctic mite Halacarellus thomasi ?: an ultrastructural and immunocytochemical study

All musculature examined in the tiny, 0.3-mm, marine Antarctic mite Halacarellus thomasi (i.e. body and appendages) appeared ultrastructurally to be of the transversely striated type with continuous Z-lines. Tubules of sarcoplasmic reticulum lay among the myofibrils. The complexity of the sarcotubular system, sarcomere lengths of over 6 μm, and the abundance of mitochondria are interpreted as signs that the mite is slow moving, but capable of considerable and sustained contraction forces, features deemed necessary in the strong currents of the frigid water prevailing in the mite's habitat. Presence and distribution of regulatory (troponin, tropomyosin, caldesmon and calponin), contractile (actin, myosin, paramyosin and miniparamyosin) and structural (alpha-actinin, titin, minititin and nebulin) proteins were determined immunocytochemically. The results are consistent with the notion of a well-functioning contractile machinery but, furthermore, provide evidence for the great importance of the structural proteins alpha-actinin, minititin and nebulin in maintaining muscle-cell stability under the environmental conditions in which the mite has to function.

Did a Blast of Sea-Floor Gas Usher in a New Age?

The end of the Paleocene epoch 55 million years ago was a puzzling time, in which tiny marine animals died, modern mammals suddenly appeared in North America, and isotopic signals indicate a shift in the global carbon cycle. Now a new mathematical model shows that a release of methane gas from the ocean floor could be at the heart of all these changes.

Two populations of the marine fish Porichthys notatus, one lacking in luciferin essential for bioluminescence

Porichthys notatus is a common benthic fish found along the Pacific coast of North America. It possesses more than 700 small dermal photophores on its head and trunk. When P. notatus collected in Monterey Bay, California, is injected subcutaneously with norepinephrine, the photophores emit a long-lasting luminescence that is readily visible to the dark-adapted eye. The light emission is due to the oxidation of luciferin (substrate) by molecular oxygen, catalyzed by luciferase. In contrast, P. notatus collected in Puget Sound, Washington, is nonluminous, even though the photophores do not differ ultrastructurally from those of the California fish. The inability of the Puget Sound fish to luminesce is due to lack of luciferin in its photophores. Luminescence capability, however, may be induced in the Puget Sound fish by the oral or intraperitoneal administration of a small amount of luciferin from the tiny luminescent marine ostracod crustacean, Vargula hilgendorfii, suggesting that the origin of luciferin in P. notatus may be from the diet. In this study, specimens of P. notatus were collected over the entire known range of the species, between November 1981 and September 1987, and the presence of luciferin in the photophores determined. The results indicate that there are two populations of P. notatus: a luciferin-deficient, nonluminescent population located north of northern California and a luciferin-containing, luminescent population extending south of Cape Mendocino, California, to Baja California, Mexico. At the northern end of the southern population, a mixture of luminescent and nonluminescent P. notatus was found.

New insights into the colonization of the deep sea: Systematics and zoogeography of the Munnidae and the Pleurogoniidaecomb. nov.(Isopoda; Janiroidea)

Summary The Munnidae (sensu Wolff 1962) are a heterogeneous group of tiny marine isopods (Asellota; Janiroidea) generally characterized by stalked eyes and an ambulatory epibenthic existence. They are found in shallow water in many parts of the world, especially in colder regions, and are a small component of the deep-sea fauna. This paper deals with the systematics and zoogeography of these isopods in two sections. The first section redefines the Munnidae and erects a new family with an old name, the Pleurogoniidae. The relationships of the genera in these two new taxa are discussed and the systematics of two related families, the Antiasidae and the Abyssianiridae, is clarified. The second section examines the zoogeographic data on the basis of this new systematic information. The Munnidae are found to be an essentially cosmopolitan, shallow-water family with a few species in the deep sea with very broad depth ranges, perhaps related to the apparent eurytopy of many munnid species. The evidence suggests ...