A capitosauroid from the Lower Triassic of South America (Sanga do Cabral Supersequence: Paraná Basin), its phylogenetic relationships and biostratigraphic implications

Surviving through the end-Permian mass extinction, stereospondyls reemerged reaching a widespread distribution during the Early Triassic. A well representative lineage of this clade, Capitosauroidea, became worldwide abundant from Early to Late Triassic, in which their first undoubtful representatives were recovered from Lower Triassic deposits. Here, we describe a new capitosauroid, Tomeia witecki gen. et sp. nov., from the Sanga do Cabral Supersequence (Paraná Basin). Although relatively incomplete, the material presents a particular combination of early and late-diverging capitosauroid characters. Supporting Tomeia witecki as a new capitosauroid, our phylogenetic analysis placed the taxon as part of a clade that comprises only Early Triassic capitosauroids, specifically as the sister-taxon of the madagascarian Edingerella madagascariensis and close to Watsonisuchus spp., from Australia, South Africa and Madagascar. The status of Tomeia witecki as a new capitosauroid from western Gondwana supports a continuous record of the Stereospondyl lineage, since their first appearance during the Middle Permian in this supercontinent. Additionally, the temporal range of the Sanga do Cabral Supersequence during the Early Triassic was specifically reinforced as Olenekian, mainly based on the overall faunal content previously reported to this unit, associated with the known temporal distribution from those taxa phylogenetically closer to Tomeia witecki.

http://zoobank.org/urn:lsid:zoobank.org:pub:7AA9F874-BED5-4A99-B098-B50656E706C1     

The spray technique: a new method for an efficient separation of fish eggs from plankton

A fast automatic new method, the "spray technique", for theseparation of fish eggs from plankton samples has been developed;each egg-sorting procedure requires less than 3 min (removalof zero up to hundreds of eggs). A targeted accuracy can beachieved by repeating the procedure. The spray method can beeasily applied onboard research vessels and it appears to copewell with different plankton compositions. Tests suggest thatthe method is 25, 60 and 110 times faster than the traditionalmanual method when using samples with low, medium and high planktoncontent. Sorted egg fractions contain less contamination byplankton particles than with the manual method. This new methodis much less prone to human error and can be standardised. However,as plankton samples vary, it is crucial to estimate regularlythe accuracy of the sorting. The method should only be usedwith standard operating procedures and pre-determined accuracytargets. Accuracy can be estimated afterwards by sorting thoroughly;checking whether any eggs had been left.     

Growth and reproduction of horse mackerel,Trachurus trachurus (carangidae)

There is a broad knowledge of the growth andreproduction of Trachurus trachurus,although important gaps still exist. Horsemackerel are a long-lived species, reaching upto 40 years of age. They have isometric growth,although the alometric parameter b mayvary throughout the year and in relation tolatitude. Growth to age 3 is rapid compared toslower growth later in life. Phenomena ofdensity dependent growth have been observed inthe northeast Atlantic. Horse mackerel are anasynchronous species. The following stages ofatresia have been validated in horse mackerel:alpha, beta, and delta. The transition infemales from the spawning state to postspawning is very fast. The spawning fraction inhorse mackerel is estimated to be between 8.3%and 20.9%. Horse mackerel have a long spawningseason (up to 8 months), which varies accordingto geography. Length at first maturity isbetween 16 and 25 cm, most commonly around21 cm. Males mature at a slightly smallerlength than females. The age at first maturityfor females has been estimated to range from 2to 4 years, depending on the geography. Batchfecundity has been estimated to range between172–209 oocytes per gram-female-weight. Femalespawning lasts between 65 and 94 days. Anindividual female can release from 5 to 16batches during the spawning period. Theestimated potential annual relative fecundityranges from 1040 to 3280 oocytes pergram-female-weight.