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Decapod crustaceans are the most diverse group of fossil invertebrates from the Upper Cretaceous Sahel Alma Lagerstätte (Lebanon, Middle East). They are mainly represented by abundant crest−bearing shrimps which were first described as Penaeus libanensis. We review this species applying the new systematic nomenclature and we propose a more complete description based on 54 unpublished specimens. This review leads to the erection of Palaeobenthesicymus gen. nov. and to the new combination Palaeobenthesicymus libanensis that is the oldest record of the family Benthesicymidae. A neotype is herein designated. Detailed comparisons with extant analogues suggest that the crest bearing shrimps inhabited relatively deep water settings most probably exceeding 150 m, at the transition between the lower circalittoral and the upper bathyal zones, under dysphotic or aphotic conditions.
The feeding ecology of the American crab Rhithropanopeus harrisii Gould, 1841 from brackish waters of the Baltic Sea was studied by analyses of the stomach repletion index (SRI) and stomach content with regard to sex, size and habitat (Dead Vistula River and the Gulf of Gdańsk). Neither the sex nor the size of an individual crab had a significant (P>0.05) influence on the SRI or on the diversity of food items found in the stomachs of R. harrisii. But the type of food consumed was significantly (P<0.05) dependent on the locality inhabited: the greater the biodiversity of the habitat, the richer the dietary composition. In Baltic coastal waters this species feeds on detritus, and also on animal and plant matter. Remains of Chlorophyta, Amphipoda, Ostracoda, Polychaeta, Gastropoda and Bivalvia were found in the stomachs of the specimens analysed.
Fragmenta Faunistica
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1997
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tom 40
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nr 27
299-305
Marine invertebrates are abundant in Korean waters. However, biological researches on marine invertebrates are limited to the faunal studies in most of the taxa. About 2 800 species of the marine invertebrates (excluding Protozoa) have been reported from Korea. In crustacean decapods, one of the well known group in Korea, 83 species of shrimps (including 16 freshwater species, and infraorders Astacidea and Palinura), 187 of crabs, and 59 of anomurans (including infraorder Thalassinidea) are known. Looking at decapod biodiversity, southern form and temperate zone form are abundant and the highest species diversity is observed in the Cheju Island waters. 29 species of shrimp, 4 of anomuran, and 24 of crab are economically important and 10 species of shrimp, 19 of anomuran, and 55 of crab are considered as rare species. Molecular phylogenetic studies based on the nucleotide sequences of macromolecules are limited to some animal groups such as anthozoans, crustacean decapods, copepods, molluscans, branchiobdellidans. With the current knowledge about the marine invertebrate fauna as well as the crustacean decapods in Korea, it is difficult to discuss the various aspects of biodiversity. Therefore, the continuous collections, inventory, faunal and systematic studies including molecular approaches one very marine invertebrates are urgently in need.
The Chinese mitten crab Eriocheir sinensis Milne-Edwards, 1854 is a newcomer to the Baltic Sea. Previous studies have shown that since the 1940s single large specimens of this species have been caught annually in Polish waters. The invasion of the Chinese mitten crab has been reported from many European countries, including Poland, where it is especially abundant in the Odra Estuary. Of 186 specimens captured in Lake Dąbie in August 1998, 45% were females and 55% males. The carapace width of these crabs varied between 53 and 88 mm and the average wet weight was 169±45.3 g.
A new species of palinuran lobster, Glyphea reticulata, from the lowermost part of the Eocene La Meseta Formation on Seymour Island, Antarctica, represents one of the stratigraphically youngest species of Glyphea. The occurrence of the last vestiges of what was previously a cosmopolitan genus in a region dominated by Pacific Ocean faunal influences is significant because the sole extant species of the Glypheidae, Neoglyphea inopinata Forest & Saint Laurent, 1975, is known only from the west Pacific.
The first record of Pseudione crenulata in the branchial chamber of Munida intermedia is reported from the southern Tyrrhenian Sea, with notes on accessory males and female morphology. The effects of this parasite on host pleopod morphology are reported. Pseudione crenulata has previously been recorded from M. tenuimana and M. rugosa, both in the Atlantic Ocean and the Mediterranean Sea.
In 1992, there took place in the Goczałkowice Reservoir intensive water blooms caused by blue-green algae with the domination of Aphanizomenon flos-aquae. They led to the dying out of the bottom macrofauna (Chironomidae, Oligochaeta, Ceratopogonidae larvae) and other animals connected with the bottom (Decapoda, Bivalvia). It is assumed that this event was due to the toxic effect of the metabolites of the blue-green algae.
The trace fossil Spongeliomorpha iberica locally occurs in the Tortonian (Upper Miocene) marine strata of the Fortuna basin in southeastern Spain, and its excellent preservation state allows a reliable reconstruction of its main morphologic features. The burrow systems are branched (but not anastomosing), and they include numerous, short, blind tunnels. The burrow walls are strongly ornamented with bioglyphs displaying a rhomboidal pattern, consisting mostly of individual “Y”−shaped scratches. Smaller, secondary bioglyphs consist of sets of less incised transverse scratches. These features allow us to assign the ichnospecies to a decapod crustacean, most likely an alpheid or thalassinidean shrimp. The burrow apparently served as a refuge for the inhabitant, which fed upon microorganisms growing on the walls of the burrow by means of scraping the interior surfaces with the maxillipeds or other mouth parts. It is also likely that the shrimp used the multiple blind tunnels to store organic material (probably plant detritus) to be used for later consumption. The crustaceans colonized mud firmgrounds, which were formed by erosion during a rapid sea−level fall. Thus, the burrows occur in direct association with erosional regressive surfaces and therefore are good stratigraphic indicators of abrupt paleoenvironmental change.
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