Shopping cartCrustaceana
Volumes & issues:
-
Decapod crustacean fauna of the Black Sea coasts of Istanbul
- + Show Description - Hide Description
-
This study was carried out as a survey of the species of decapod Crustacea found along the Black Sea coasts of Istanbul. It also aims to report on some of their ecological properties. Samples were collected at 36 stations during 2000 and 2001 from depths of 0.5-65 m using a scoop net, dredge, beam-trawl, or trammel net. A total of 15 species of decapod crustaceans was identified. One of these, Philocheras fasciatus (Risso, 1816), is herein reported for the first time from the Turkish coastal waters of the Black Sea. Primary hydrographic conditions such as temperature (range 8.0-21.8°C), salinity (16.7-17.8‰), and dissolved oxygen (4.5-9.0 mg/l) were recorded at each sampling occasion.
-
Species composition, abundance and biomass of Copepoda in plankton of the northern Levantine Basin (eastern Mediterranean)
- + Show Description - Hide Description
-
Changes in species composition, abundance and biomass of copepods were monitored weekly over the year 1998 in shelf waters of the northern Levantine Basin. A total of 192 copepod species belonging to 61 genera were identified during the course of this study. Thirty-six species are reported for the first time from the region, including three new species. Copepod abundance ranged from 215 individuals m−3 in early March to 2220 individuals m−3 in late March, whereas the biomass ranged from 4 mg m−3 in mid-January to 22 mg m−3 in mid-February. The copepod fauna was found to be most species-rich on 4 November (Margalef’s Index d = 7 . 4 ) and least on 10 March ( d = 3 . 3 ). The index was found low during spring and autumn with lowest levels obtained during the stratification period from September to October. The diversity was found to be highest on 18 February (Shannon-Wiener Index H ′ = 2 . 9 ) and lowest on 31 March ( H ′ = 1 . 6 ). Higher index values were characteristic of the winter period. A proportional representation of the species among their populations was well established during February whereas the best situation was met on 3 March and the most unbalanced situation at the end of March. Multivariate analyses have shown the formation of distinct seasonal communities of copepod species throughout the year. The observed seasonality in community structure is suggested to be a result of wide range changes in temperature throughout the year. The dominant species observed during late winter and spring were Oithona nana, Oithona sp., Oncaea media, Oncaea sp., Calocalanus elegans, Euterpina acutifrons and Oncaea zernovi, respectively. Calocalanus sp., C. elegans, Triconia dentipes, Oncaea sp., Oithona nana, Clausocalanus furcatus, and Temora stylifera were dominant during summer, whereas Oncaea sp., Calocalanus sp., Oithona nana, Clausocalanus paululus, C. furcatus, Parvocalanus sp., and Calocalanus elegans dominated the autumn and early winter populations. Sharing similar species with the Indo-Pacific region gives the copepod fauna of the Levantine Basin, at least in part, a subtropical affinity.
-
Morphometric relationships of juvenile Metapenaeopsis goodei (Smith, 1885) (Decapoda, Penaeidae) in the Yucatan Peninsula, Mexico
- + Show Description - Hide Description
-
The small penaeid shrimp Metapenaeopsis goodei (Smith, 1885) is widely distributed along the Atlantic Ocean, yet information on its morphometric features is scarce or non-existent. This study evaluated differences in the morphometric relationships between sexes of juvenile (carapace length mean: 6.8 mm, range: 3 to 10.5 mm) in a nursery ground of northeastern Yucatan peninsula, Mexico. The morphological features studied were carapace length (CL), total length (TL), rostrum length (RL), relative rostrum length (RL∕CL ratio), and total wet weight (W). About 19% of females ( n = 207 ) and 54% of males ( n = 167 ) had size classes of complete sexual maturity reported for this species, i.e., >8 and >6 mm CL, respectively. Analysis of covariance detected significant differences between sexes for the TL-CL, RL-CL, RL/CL-CL and CL-W relationships. The coefficient b (slope) of the morphometric relationships decreased about 4 to 20% in females relative to males. The TL-CL, RL-CL and CL-W relationships showed positive allometry for both sexes, but more strongly in males, suggesting that as juveniles increase in CL the males become larger, heavier, and with longer rostrum than females, although males did not reach the same maximum mean CL as females. The positive allometric growth for the CL-W relationship suggests that weight increases more than length, probably because of the abundant food supply on the nursery ground. Results from the current study indicate that separation of morphometric relationships for females and males is necessary for M. goodei that inhabit nursery grounds. Sexual dimorphism in morphometry appears to reflect development to sexual maturity of juveniles in shallow inshore nursery grounds, before migrating to offshore adult habitats.
-
Fine scale meiofaunal distribution around burrows of ocypodoids (Decapoda, Ocypodoidea) in tidal flat sediments
- + Show Description - Hide Description
-
In tidal flat sediments, larger invertebrates often modify the sedimentary environment in a manner that causes smaller animals, such as meiofauna, to become more abundant. In other words, macrofauna can “promote” meiofauna. In summer (August) and autumn (November/early December) 2007, we investigated centimetre-scale horizontal and vertical profiles of total metazoan meiofaunal abundance and community structure around burrows of Uca lactea (De Haan, 1835) (fiddler crabs) and Scopimera globosa (De Haan, 1835) (sand bubbler crabs) on an intertidal sandflat of the Amakusa Islands, western Japan. Meiofaunal community structure changed significantly with sediment depth around burrows of U. lactea in both seasons, whereas vertical differences were less clear for S. globosa. Although no evidence was found that total meiofaunal abundance or the abundances of certain taxonomic groups were positively influenced by burrows of S. globosa, the abundance of nematodes in subsurface sediment around burrows of U. lactea was significantly higher than in controls in autumn. High concentrations of fresh organic matter had not accumulated in the sediment around burrows of either species of crab. Uca lactea, however, made its burrows in significantly finer sediment than did S. globosa. One possibility is that differences in meiofaunal distribution in sediment around the burrows of the two crabs were the result of habitat and behavioural differences between the species.
-
Morphological and functional characteristics of setae involved in grooming, water uptake and water circulation of the soldier crab Mictyris guinotae (Decapoda, Brachyura, Mictyridae)
- + Show Description - Hide Description
-
This study was focused on the relationship between behaviour and morphological characters of the soldier crab Mictyris guinotae, using a functional morphological approach. The behaviour patterns of M. guinotae involved in water uptake and water-circulation were recorded by video camera and the setae involved in those two activities were described in detail. Furthermore, the crab’s grooming behaviour engaged in the cleaning of the surface of the third maxilliped was determined. The setae were classified into six types: denticulate, pappose, plumose, normally setulate, serrate, and simple setae. Among these, the denticulate setae were found on the chelipeds and the simple setae on the posterior margin of the carapace and on the anterior border of the first abdominal somite. M. guinotae inserted the setae located on the posterior border of the carapace margin and the anterior border of the first abdominal somite into the sandy substratum, and expelled water from its exhalant apertures and mouthparts. The water then flowed along the surface of the third maxilliped onto the abdomen. The crab exhibited a grooming behaviour to clean the surface of the third maxilliped after expelling water, by using the carpus and propodus of the cheliped when the surface of the third maxilliped had become covered by mud. We conclude that simple setae may have the function of collecting water from the substratum by capillary action, and the denticulate setae apparently have a grooming function. Moreover, also (the flow of) water may increase grooming efficiency, when the flow continues as the crabs groom the surface of their third maxilliped.
-
The first record of Gammarus aequicauda (Martynov, 1931) (Amphipoda, Gammaridea) in the estuary of the river Jadro (Adriatic Sea, Croatia)
- + Show Description - Hide Description
-
Gammarus aequicauda (Martynov, 1931) (Amphipoda, Gammaridea) is known as an euryhaline and euryvalent species in warm temperate waters, including lagoon systems and shallow coastal waters. The estuary of the River Jadro is a part of Kaštela Bay (Adriatic Sea), and after construction works on the downstream watercourse of the river, some ecological conditions have changed. A concrete barrier that was built decreases the influence of fresh water, which resulted in an increased salinity and a raised level of dissolved organic compounds. Such conditions were favourable for macroalgae, especially Enteromorpha sp., thus overgrowing riversides and providing amphipods with food and protection against predators. There are no earlier published data confirming the presence of G. aequicauda in Kaštela Bay. This is the first record of G. aequicauda from the River Jadro estuary as well as the first record of the species for Croatian rivers in general.
-
Acute toxic effects of deltamethrin on red swamp crayfish, Procambarus clarkii (Decapoda, Cambaridae)
- + Show Description - Hide Description
-
In order to know the acute toxic effects of the synthetic pyrethroid deltamethrin on red swamp crayfish, Procambarus clarkii, an acute toxicity test was carried out. The results showed that the 24, 48 and 96 h LC50 values were 0.156, 0.099 and 0.056 μg/l, respectively. The abnormal behavioural responses and toxic signs can be described as typical neurotoxic symptoms, characterized by ataxia, hyperexcitation, convulsion, and paralysis. The residue of deltamethrin in haemolymph, gill, muscle, and liver of the crayfish was under the limit of quantification of the GC-MS method after a 96-h exposure to 0.05 μg/l deltamethrin and a 24-h exposure to 0.1 μg/l deltamethrin. Besides that, the sublethal effects caused by deltamethrin were assessed by using cytochrome c oxidase (CCO) activity, lactase dehydrogenase (LDH) activity, and lactic acid levels as sensitive biomarkers. Results showed that 24 h exposure to 0.1 μg/l deltamethrin significantly inhibited the CCO activity ( P < 0 . 05 ), but increased LDH activity ( P < 0 . 05 ) and the lactic acid level ( P < 0 . 05 ) in gills, which further indicated that the aerobic metabolism was inhibited by deltamethrin in the gill while the anaerobic metabolism was stimulated.
-
Land crabs (Decapoda, Brachyura, Gecarcinidae) on Isabel Island, Mexico, including a new record, and its relation to the removal of invasive rats
- + Show Description - Hide Description
-
-
Ecdysozoans, articulates, and the needle in a haystack
- + Show Description - Hide Description
-
back to top