Wyniki wyszukiwania - BazTech

1

Marine fishes (Elasmobranchii, Teleostei) from the Glendon Limestone Member of the Byram Formation (Oligocene, Rupelian) at site AWa-9, Washington County, Alabama, USA, including a new species of gobiid (Gobiiformes: Gobiidae)

Ebersole Jun A., Cicimurri David J., Stringer Gary L.

Acta Geologica Polonica

|

2021

|

Vol. 71, no. 4

481--518

EN

The Oligocene (Rupelian) Byram Formation (Vicksburg Group) in Alabama, USA, is divided into three members, including (in ascending order) the Glendon Limestone, unnamed marl, and the Bucatunna Clay. The Oligocene marine units in Alabama have been historically under-investigated, but bulk samples recently obtained from Glendon Limestone Member exposures at site AWa-9 in Washington County yielded 20 unequivocal elasmobranch and teleost taxa. This surprisingly diverse paleofauna, based on isolated teeth, bones and otoliths, includes the new taxon, Gobiosoma? axsmithi sp. nov., as well as “Aetomylaeus” sp., Albula sp., Aplodinotus gemma Koken, 1888, Ariosoma nonsector Nolf and Stringer, 2003, Balistidae indet., Citharichthys sp., Myliobatoidei indet., Diretmus? sp., Hemipristis sp., Negaprion aff. N. gilmorei (Leriche, 1942), Pachyscyllium sp., Paralbula sp., Physogaleus sp., Preophidion meyeri (Koken, 1888), Sciaena pseudoradians (Dante and Frizzell in Frizzell and Dante, 1965), Sciaenops? sp., Sparus? elegantulus Koken, 1888, Sphyraena sp., and Syacium sp. Additional remains were recovered but could not be identified beyond undetermined Elasmobranchii or Teleostei. All these taxa represent first occurrences within the Glendon Limestone Member in Alabama, and the “Aetomylaeus” sp., Pachyscyllium sp., Paralbula sp., and Sciaenops? sp. specimens represent the first occurrences of each in the Oligocene of the Gulf Coastal Plain of the USA. We also report the first record of Oligocene Paralbula Blake, 1940 teeth, and the first occurrence of an Oligocene member of the Balistidae in the Western Hemisphere. This marine vertebrate assemblage indicates that the Glendon Limestone Member at site AWa-9 represented a subtropical to temperate, middle shelf paleoenvironment with a paleowater depth interpreted as 30–100 m.

2

Comparison of Hard Structures for Age Estimation and Chemical Composition Analysis of Otoliths of Perch from Lake Trzesiecko under Reclamation

Lampart-Kałużniacka M., Heese T.

Rocznik Ochrona Środowiska

|

2017

|

Tom 19

809--823

EN

The study revealed that the ray of the dorsal fin D was the most readable structure for age estimation in perch from Lake Trzesiecko. Otoliths turned out to be more problematic structures. Age estimation based on otoliths was difficult, and the structures were very brittle, which made it impossible to prepare microscope slides. This was probably related to their crystal structure. Growth rate could only be calculated based on the scale. In the case of older specimens aged 5+ and more, however, it was difficult to identify the mark related to the first year of life due to the low readability of the middle part of the scale. This results in inflated results obtained for group L1. Studies on age of fish should be conducted based on several structures due to the possibility of verification of the obtained results. Performing the analysis of only one selected element results in high variability of the obtained data, and therefore inaccurate conclusions. The recorded presence of iron atoms in the otoliths suggests the accumulation of the metal resulting from the application of chemical compounds by man in living organisms.

PL

Prezentowany Porównanie przydatności struktur twardych do szacowania wieku i analiza składu chemicznego otolitów okonia Perca fluviatilis (L.) pochodzącego z rekultywowanego Jeziora Trzesiecko. Prowadzone badania wskazały, że najbardziej czytelną strukturą do szacowania wieku u okonia pochodzącego z Jeziora Trzeskiecko był promień płetwy grzbietowej D. Otolity okazały się strukturami bardziej problematycznymi. Trudno było na ich podstawie szacować wiek, jednocześnie były bardzo „kruche”, co uniemożliwiło wykonanie na ich podstawie preparatów mikroskopowych. Prawdopodobnie było to związane z ich budową krystaliczną. Tempo wzrostu można było obliczyć tylko na podstawie łuski. Stąd rozsądne wydaje się działanie w którym, szacowanie wieku i wyznaczanie tempa wzrostu prowadzi się w oparciu o kilka elementów. Opieranie badań tylko na jednej wybranym elemencie, skutkuje dużą zmiennością uzyskiwanych wyników. Świadczyć o tym może, chociażby brak zgodności danych, uzyskiwanych w czasie badań, prowadzonych przez różne osoby, które szacowały wiek dla ryb w oparciu o te same struktury twarde. Odnotowanie atomów żelaza w otolitach, może być efektem kumulacji tego metalu w organizmach żywych, a źródłem jego jest związek chemiczny, aplikowany do jeziora w celu poprawy jego stanu ekologicznego.

3

Differences in the maturation level among life histories of the Japanese eel Anguilla japonica in the Nagata River, Japan

Chino N., Imai C., Sakai H., Arai T.

Oceanological and Hydrobiological Studies

|

2017

|

Vol. 46, No. 4

472--477

EN

In order to understand the silver eel migration behavior of the Japanese eel Anguilla japonica, the life history of both the yellow stage (immature stage) and the silver stage (early maturing stage) was examined during the silver eel migration period, using otolith microchemical analysis of strontium (Sr) and calcium (Ca) concentrations. The mean Sr:Ca ratios in A. japonica from the elver mark to the otolith edge indicate eels of several general categories of migratory histories, including sea eels (average Sr:Ca ratios, ≥ 6.0 × 10-3), estuarine eels (average Sr:Ca ratios, 2.0 × 10-3 ≤ Sr:Ca < 6.0 × 10-3) and river eels (average Sr:Ca ratios, < 2.0 × 10-3), based on the criteria reported previously in A. japonica. A significant negative correlation was observed between the gonadosomatic index (GSI) and the mean Sr:Ca ratios during the growth phase after recruitment. Gonads of river eels were more developed compared to eels with other migratory histories. It thus appears that the maturation level for the silver eel migration to the open ocean varies depending on the life history.

4

Growth of the young flounder (Platichthys flesus) in inshore shallow waters of the Gulf of Gdańsk

Sapota M.R., Mudrak S.

Oceanological Studies

|

1998

|

Vol. 27, No. 3

19-29

EN

The age and rate of growth of the flounder from inshore shallow waters of the Gulf of Gdansk (from shore to 1-m depth) have been investigated. Mainly the flounder from 0 and 1-year age group exists in this zone. Flounders from 0-year age group enter shallow waters of the Gulf of Gdansk in June or July. They stay in this area till the end of the year. Flounders from 1-year age group are represented in the investigated zone all year. Bigger individuals from this group migrate into deeper waters.