Pleistophora hippoglossoideos. [Descriptions of Fungi and Bacteria].

A description is provided for Pleistophora hippoglossoideos, which infects Hippoglossoides platessoides, American plaice (family Pleuronectidae) and Solea solea, the Dover sole (family Soleidae), in the North Atlantic, Baltic Sea and Arctic Ocean. Some information on its morphology, dispersal and transmission and conservation status is given, along with details of its geographical distribution (Europe (Baltic Sea, Norway, UK) and North America (Canada, Nova Scotia)) and hosts (Hippoglossoides platessoides, H. limandoides and Solea solea).

Spatiotemporal variation in maturation: a case study with American plaice (Hippoglossoides platessoides) on the Grand Bank off Newfoundland

Fisheries management usually does not explicitly account for spatial variation in life history traits within populations. However, for some stocks this spatial variation may be substantial. We develop a spatiotemporal generalized linear model and fit the model to a long time series of maturation data for American plaice (Hippoglossoides platessoides) on the Grand Bank off Newfoundland and Labrador. The spatiotemporal correlation structure improves estimation of small-scale spatiotemporal variation in maturity across locations and times with limited or few samples. We test how American plaice maturity varies at three different spatial resolutions. We find improvements in model fit when decreasing spatial scales for higher spatial resolution due to high levels of spatial heterogeneity in American plaice maturity at age and size. Modeling variation in life history traits at the appropriate spatial and temporal scales is necessary for understanding population dynamics and developing appropriate fisheries management strategies.

Does increased information about reproductive potential result in better prediction of recruitment?

The relationship between stock size and recruitment is an essential element in the understanding of the productivity of a population. However, predicting the number of recruits produced by a population has proven to be a difficult challenge. This may in part be a result of poor estimation of reproductive potential (RP). We determined if including increased information on reproductive biology in indices of RP results in better predictions of recruitment. We investigated some of the conditions that lead to better (or worse) recruitment prediction when more biologically complex indices of RP are used. Data from four populations in the Northwest Atlantic were examined: southern Grand Bank (NAFO Division 3NO) cod ( Gadus morhua ), Flemish Cap (NAFO Division 3M) cod, Newfoundland (NAFO Division 3LNO) American plaice ( Hippoglossoides platessoides ), and Greenland halibut ( Reinhardtius hippoglossoides ) (NAFO Subarea 2 + Division 3KLMNO). Stock–recruit models paired with complex indices of RP gave a better estimate of recruitment in slightly more than half of the tests conducted. When there were larger trends in the reproductive biology (maturity at age, sex ratio and egg production), more complex indices of RP were more likely to provide a better estimate of recruitment.