The curio trade in marine fishes has not previously been quantitatively analysed. As a contribution towards understanding the scale and conservation impact of such trade we summarize import and export data from the United States Fish and Wildlife Service for 1997-2001. At least 32 fish species were involved in the USA's international trade in curios, of which 24 were included on the 2004 IUCN Red List of Threatened Species, with categorizations ranging from Endangered to Data Deficient. The USA apparently imported an annual total of approximately one million fish and 360 tonnes of fish parts, worth more than USD 1.7 million, although total volume declined over the 5 years of data.Fish curios imported to the USA reportedly came primarily from Taiwan and the Philippines, with 95% of curios obtained from wild populations. The three marine fish groups most traded for curios were sharks, seahorses and porcupinefishes. The value per individual fish fluctuated across years, with a considerable increase in the value of dried seahorses from 1997 to 2001. The trade probably adds to conservation concerns for at least some species.
A review of all available specimens of fossil fishes from the classic Pennsylvanian Joggins locality of Nova Scotia, Canada, reveals the existence of a diverse community of chondrichthyans (xenacanthids, ctenacanthids and the enigmatic Ageleodus), acanthodians (gyracanthids), sarcopterygians (rhizodontids, megalichthyids, rhizodopsids and dipnoans) and actinopterygians (haplolepids). Reassessment of supposed endemic species (Ctenoptychius cristatus, Sagenodus plicatus, Gyracanthus duplicatus) indicates they are invalid, and overall, the assemblage comprises cosmopolitan taxa that were widespread around the coasts of tropical Pangaea. Strontium isotope analysis of fish remains and a critical study of their facies context suggest that these fish communities occupied bodies of water with salinities across the marine-freshwater spectrum. This preponderance of euryhaline forms implies a community structure quite distinct from that of today and might represent a transitory phase prior to the establishment of fully freshwater fish communities. Interpretation of fish ecology provides further evidence that the Joggins Formation was deposited in a paralic setting, and the recognition of one previously undetected brackish incursion strengthens the link between sedimentary cycles at Joggins and Milankovitch-induced glacio-eustatic change. Furthermore, interregional correlation of these marine transgressions supports palynostratigraphical arguments for an early Langsettian age for the Joggins Formation. This places tighter constraints on the age of the earliest known crown amniote, Hylonomus lyelli, an important calibration point used in phylogenomic studies.
. 2014: From near extinction to recovery: Late Triassic to Middle Jurassic ammonoid shell geometry. Lethaia, Vol. 47, pp. 337-351.The Triassic-Jurassic extinction resulted in the near demise of the ammonoids. Based on a survey of ammonoid expansion rates, coiling geometry and whorl shape, we use the Raup accretionary growth model to outline a universal morphospace for planispiral shell geometry. We explore the occupation of that planispiral morphospace in terms of both breadth and density of occupation in addition to separately reviewing the occurrence of heteromorphs. Four intervals are recognized: pre-extinction (Carnian to Rhaetian); aftermath (Hettangian); post-extinction (Sinemurian to Aalenian) and recovery (Bajocian to Callovian). The pre-extinction and recovery intervals show maximum disparity. The aftermath is marked by the disappearance of heteromorphs and a dramatic reduction in the range of planispiral morphologies to a core area of the morphospace. It is also characterized by an expansion into an evolute, slowly expanding part of the morphospace that was not occupied prior to the extinction and is soon abandoned during the post-extinction interval. Aftermath and post-extinction ammonoid data show a persistent negative correlation whereby rapid expansion rates are associated with narrow umbilical widths and often compressed whorls. The permanently occupied core area of planispiral morphospace represents generalist demersals whose shells were probably optimizing both hydrodynamic efficiency and shell stability. All other parts of the planispiral morphospace, and the pelagic modes of life the shells probably exploited, were gradually reoccupied during the post-extinction interval. Planispiral adaptation was by diffusion away from the morphospace core rather than by radical jumps. Recovery of disparity was not achieved until some 30 Myr after the extinction event.
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