John S Ryland

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 Zoanthid taxonomy is currently in a state of chaos, with many described species very few of which can be reliably identified. As part of a genetically based, objective reappraisal of the number of northern Australian species, a total of 355 zoanthid specimens were collected from 19 localities in the Great Barrier Reef and Torres Strait during 1992–1994.(More)
Schizoporella japonica Ortmann was described from Japan but was subsequently introduced on Pacific oysters to the Pacific coast of North America, where it is now well established. In this paper we record it for the first time in European waters. The initial discovery was in a marina at Holyhead, North Wales, in July 2010 but S. japonica has since been(More)
Seven different types of nematocyst are detailed and illustrated from the Zoanthidea. We studied the size population structure of nematocyst capsules: how they are affected by preservation, and how and what should be measured. Populations of two types, large holotrichs and p-mastigophores, from the mesenterial filaments of Protopalythoa heliodiscus and Pr.(More)
Gametogenesis and spawning have been studied since 1986 in a population of Protopalythoa sp. (Anthozoa, Zoanthidea) from Orpheus Island, Great Barrier Reef. Fertile zooids were gonochoric or hermaphroditic with oocytes and sperm vesicles intermingled in the same mesentery; colonies were single sex or mixed. Oocytes arose in macrocnemes below the(More)
Colonial zoanthids are a conspicuous feature of the subtropical rocky intertidal in KwaZulu-Natal but those of the genus Zoanthus have a confused taxonomy with 10, difficult to separate, nominal species described from the region. This paper presents an analysis of polyp size, measured as mean diameter determined photographically from the number of polyps(More)
The zooxanthellate macrocnemic zoanthid Parazoanthus parasiticus lives at densities of 3–10 cm−2 in the chimney sponge Callyspongia vaginalis in Bermuda. It is gonochoric and oviparous. Small oocytes appear in the mesenteries in February–March, grow slowly at first, then increase volume rapidly as seawater temperature passes 27 °C in July. In 1993, oocytes(More)
Semper's larvae were obtained from <300 out of ∼1800 plankton tows taken in the world's oceans (1964–1993). Zoanthellae (larvae of Sphenopidae) occurred at 217 stations and zoanthinae (larvae of Zoanthidae) at 86, the two larval types showing distributions clearly delimited by a minimum sea temperature (∼22 °C for zoanthellae, ∼18 °C for zoanthinae; a(More)
Epizoanthus is a poorly known zoantharian genus in need of further study. Benthic surveys have shown that E. papillosus (until recently considered rare) is quite abundant in the Celtic Sea, Minches and northern North Sea, occurring as carcin-oecia formed in association with Anapagurus laevis (Anomura, Paguridae) and as smaller free-living colonies. It is(More)