The Magnitude of Global Marine Species Diversity

Background: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered. Results: There are ∼226,000 eukaryotic marine species described. More species were described in the past decade (∼20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are ∼170,000 synonyms, that 58,000–72,000 species are collected but not yet described, and that 482,000–741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7–1.0 million marine species. Past rates of description of new species indicate there may be 0.5 ± 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science. Conclusions: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

Disjunct Distributions of Halobates (Hemiptera: Gerridae) in the Pacific Ocean

Five species of Halobates are specially adapted to a pelagic life. They all occur in the Pacific Ocean, each with a well-defined zoogeographical range. Only two species were caught in a series of samples collected between Hawai'i and Tahiti: H. sericeus Eschscholtz, with an amphitropical distribution, and H. micans Eschscholtz, occupying the equatorial zone separating the northern and southern populations of the former. This disjunct distribution pattern may be maintained by zonal equatorial current systems. Although mixing of the two species may occur during seasonal weakenings of the currents, the two populations of H. sericeus appear to be quite separate, with little or no possibilities of genetic exchange

Mass Oviposition and Egg Development of the Ocean-Skater Halobates sobrinus (Heteroptera: Gerridae)

We report the first observation of mass oviposition by the ocean-skater Halobates sobrinus White in the eastern tropical Pacific Ocean. We netted, in one scoop, 833 insects and a single egg mass with an estimated 70,000 eggs on a plastic gallon (3.785-liter) milk jug. Evidently anthropogenic debris could provide potentially important oviposition substrates for Halobates spp. in the open ocean. Freshly laid eggs incubated at 26-32°C hatched within 8-10 days. Eggs kept at temperatures below 22°C did not hatch even after 20 days

The Endemic Sea-Skater HALOBATES ALLUAUDI BERGOTH, 1893 (HEMIPTERA: GERRIDAE) in the Seychelles

ABSTRACT - The sea-skater Halobates alluaudi Bergroth, 1893, endemic to the Seychelles, was collected from the islands of Mahe, Praslin, La Digue, and Curieuse, but not from Cousin, Ste. Anne or Cerf. Large flotillas, consisting of both nymphs and adults, were found only associated with mangroves or under overhanging coastal vegetation. Adult females were rare in all the samples and were completely absent from samples from Praslin.&nbsp

A PRELIMINARY STUDY ON THE TAXONOMY AND BIOLOGY OF THE MALAYAN GERRIDAE (HEMIPTERA-HETEROPTERA)

Bachelor'sBACHELOR OF SCIENCE (HONOURS

The Ocean-Strider HALOBATES (Heteroptera: Gerridae)

The genus Halobates, first described by Eschscholtz (1822) was monographed by Herring (1961), with notes on biology and known distribution of the 38 known species and a key for their separation. More recently Savilov (1967) provided additional information on the distribution of the Pacific species. Our knowledge on the biology and ecology of these unique oceanic insects is very scanty.Our knowledge of the limits of distribution of oceanic Halobates is still very incomplete. From available data they seem to be largely determined by the climatic conditions of the water, and there is no doubt that wind as well as water current play an important role in their distribution. An understanding of the relative importance of these two dispersive factors may help us to understand the distributions not only of Halohates but also of other pleuston organisms