Frederick McCoy and the Phylum Brachiopoda

Sir Frederick McCoy, during a long career involved with taxonomy, contributed extensively to the knowledge of the fossil record of the Phylum Brachiopoda, From his classic early monographs on the fossil faunas of the Carboniferous and Silurian of Ireland, to his later works in Victoria where important new species were described and illustrated, McCoy demonstrated the same care, meticulous rigour and quality of illustrations that typified all his work. His contributions on the Brachiopoda are of high and long-lasting significance but form only part of his much broader contribution to palaeontology.

Frederick McCoy and the naturalist tradition

From August 1869 until May 1871, an anonymous naturalist under the pseudonym 'Microzoon' published a superb series of articles in a weekly Melbourne newspaper, The Australasian. The author was undoubtedly Frederick McCoy. The Microzoon articles provide a valuable early record of
aspects of the natural history of Victoria, in particular the bird life, but also covering a selection of other topics including snakes, insects, fish, molluscs, geology, palaeontology and stratigraphy.

Frederick McCoy`s Mount Macedon Property

In the later part of his life Frederick McCoy selected and developed a bush block on the slopes of Mount Macedon. The conditions for purchase required him to plant and foster the growth of various northern hemisphere trees and shrubs. He duly cleared part of the block, planted trees, shrubs and
grass, put up fencing, constructed a small reservoir and laid pipes. In 1876, having fulfilled government requirements, he purchased the property and retained ownership until 1890.

Frederick McCoy and his contributions to stratigraphical palaeontology

Sir Frederick McCoy made a significant contribution to the foundation of stratigraphical palaeontology. He carried out extensive taxonomic work sorting, naming and describing the Palaeozoic fossils of Ireland and Britain, and also played a decisive role in the debate between Adam Sedgwick and Roderick Murchison on where to draw the boundary between the Cambrian and Silurian systems. On his arrival in the Colony of Victoria in December 1854 he found that, contrary to the expectations of most European scientists, much of the stratigraphy and palaeontology paralleled that in the Northern Hemisphere. Hence McCoy was the first to confirm that the geological column was a global phenomenon.

Growth rates of the infaunal bivalve Soletellina alba (Lamarck, 1818) (Bivalvia: Psammobiidae) in an intermittent estuary of southern Australia

Caging and a mark–recapture design were used to estimate the growth rate of the brittle, infaunal bivalve Soletellina alba in the Hopkins River estuary. The growth of both caged and uncaged individuals was monitored at three sites near the mouth of the estuary over 180 days. Growth rates did not differ for caged and uncaged bivalves, or for bivalves subject to different amounts of handling, or between sites. Growth did differ between consecutive time intervals, which was attributable to negligible growth occurring during the colder months of autumn/winter. Comparisons of the condition (as indicated by total mass for length³) of S. alba were inconsistent between sites for caged and uncaged bivalves and for those subject to different amounts of handling. Soletellina alba is a rapidly growing bivalve with mean growth rates for the three time intervals being 0.04±0.002 mm day⁻¹ in summer, 0.02±0.001 mm day⁻¹ in autumn and 0.03±0.001 mm day⁻¹ from summer to winter. Using existing literature, it was shown that a significant relationship exists between maximum shell length and onset of sexual maturity in bivalve molluscs. This relationship predicts that S. alba should reach the onset of sexual maturity at 15.8 mm length. Therefore, it appears that it may be possible for juvenile S. alba (<1 mm) to grow, reach sexual maturity and reproduce in between annual mass-mortality events caused by winter flooding.

Effect of lowered salinity on the survival, condition and reburial of Soletellina alba (Lamarck, 1818) (Bivalvia: Psammobiidae)

Mass mortalities of fauna are known to occur in estuarine environments during flood events. Specific factors associated with these mortalities have rarely been examined. Therefore, the effect of exposing, to lowered salinities, an infaunal bivalve that is susceptible to mass mortalities during winter flooding in a southern Australian estuary was tested in the present study. In a laboratory experiment, low salinities (≤6 parts per thousand [ppt]), which mimicked those expected during flood events in the Hopkins River estuary, were shown to affect Soletellina alba, both lethally and sublethally. All bivalves died at 1 ppt, while those at 6 ppt took longer to burrow and exhibited a poorer condition than those at 14 and 27 ppt. The limited salinity tolerance of S. alba suggests that lowered salinities are a likely cause of mass mortality for this species during winter flooding.

Recruitment of the infaunal bivalve Soletellina Alba (Lamark,1818) (Bivalvia: Psammobiidae) in response to different sediment types and water depths within the intermittently open Hopkins River estuary

Studies examining recruitment processes for soft-sediment macroinvertebrate fauna in intermittent estuaries are rare and most studies of active habitat selection have been tested in the laboratory rather than the field. The present field study examined whether recruitment of the infaunal bivalve Soletellina alba was influenced by water depth and sediment particle size in the intermittent Hopkins River estuary, southern Australia. The number of recruits in sediment trays differed between water depths, but active habitat selection was not evident across treatments of varying sediment particle size. The use of sediments with varying particle sizes also provided an opportunity to identify potential discontinuities in body-size distributions of recruits associated with varying habitat architecture. The length (mm) of recruits was converted to the same scale used to express sediment particle size (i.e. phi units: phi = − log2 of sediment particle size). The size of recruits differed across water depths, but did not differ across treatments with fine (phi = 3) versus coarse (phi = 1) sediment, and no relationships were apparent between bivalve size and sediments consisting of varying particle size. These patterns of recruitment do not correspond with the distribution of adult S. alba within the Hopkins River estuary. Previous sampling has shown that abundances of juvenile and adult S. alba are variable across time, site and water depth, but are often greater at the deeper water depth (1.05 m below the Australian Height Datum). However, recruitment during the present study was greatest at the shallower water depth (0.05 m below AHD), and the apparent absence of active habitat selection suggests that the distribution of adults is unlikely to be attributable to differences in recruitment associated with sediments of varying particle size.

Spatial and temporal changes in abundance of the infaunal bivalve Soletellina alba (Lamark, 1818) during a time of drought in the seasonally-closed Hopkins River Estuary, Victoria Australia

The infaunal bivalve Soletellina alba is susceptible to mass mortalities during annual winter flooding in the Hopkins River Estuary, southern Australia. Periods of low salinity (≤1) are the likely cause of these mass mortality events, which can occur in seasonally-closed estuaries when high winter flows are sufficient to flush all salt water from the estuary. Core samples of S. alba were collected from two water depths across four times and at three sites near the mouth of the estuary. Minimal to zero abundances of large S. alba (>1 mm) were expected to be sampled, particularly at the shallower water depth, during a typical winter flood event. However, the present study occurred during a period of drought, which led to the absence of winter flooding. This absence of winter flooding prevented the occurrence of lethal salinities (i.e. ≤1) in the estuary during this period and a greater number of living S. alba adults were sampled. Abundances of juvenile and adult S. alba were still variable, even in the absence of winter flooding, and reflected an interaction between date, site and water depth. However, no mass mortalities of adults were observed during the drought conditions in contrast to what occurs during typical winter flood events and provides support for the hypothesis that winter flooding is responsible for past mass mortalities.