A new species of the mud shrimp genus Axianassa Schmitt, 1924 (Decapoda: Gebiidea: Laomediidae) from Japan

The laomediid mud shrimp genus Axianassa Schmitt, 1924 is currently represented by 12 species worldwide. In this study, a new species of the genus, A. microlepis, is described and illustrated on the basis of two female specimens obtained from Awaji Island, eastern part of the Seto Inland Sea, Japan, at depth of 8 m. The type specimens were collected by means of an airlift suction sampler, which enables collection of infauna in subtidal soft sediments. The new species, representing the fourth species of the genus known from the western Pacific, is readily distinguished from other congeners by the unique structure of the antennal scaphocerite (short, non-dagger shaped, terminally rounded or having spine and blade), faintly crenulate rostral margins and the presence of a small lateral notch on the uropodal endopod. An amended identification key to the species of Axianassa and Heteroaxianassa Sakai, 2016 is provided.

A new species of the alpheid shrimp genus Automate de Man, 1888 (Decapoda: Caridea) from Japan

A new species of the alpheid shrimp genus Automate de Man, 1888, A. awaji, is described on the basis of an ovigerous female holotype and three paratype specimens (sex not determined) from Awaji Island, Hyogo Prefecture, Japan. The specimens were collected from soft sediments on a shallow subtidal flat (depth 4–8 m) using an airlift suction sampler. The new species is referred to the A. evermanni Rathbun, 1901 species group, in which seven species are currently included, from various parts of the world. Automate awaji n. sp. is characterized by the combination of the following characters: eye with cornea relatively small, in lateral and subdistal position on eyestalk; antennal scaphocerite with distolateral spine not exceeding rounded distal blade; ultimate article of maxilliped 3 with longitudinal row of setae on dorsolateral surface; cheliped ischia without spiniform setae on dorsal and ventral margins; major chela of type I smooth, not rugose or tuberculate on dorsal and ventral margins, fingers not gaping; carpus of pereopod 2 with proximal-most article less than half-length of second article; propodus of pereopod 5 with grooming apparatus consisting of closely spaced transverse rows of stiff setae. It is the fourth representative of the genus Automate reported from Japan. A brief overview on Japanese species of Automate is also given.

‘Simple’ can be good, too: testing three hard bottom sampling methods on macrobenthic and meiobenthic assemblages

Subtidal hard bottoms are of particular scientific and economic value as they are highly productive systems. They are less well studied compared with soft bottoms, as they often require manual sample collection via scuba diving. Although a multitude of sampling devices is available for soft bottoms, only a few are suitable for hard substrates, and their performance is largely unstudied. In the present study, three hard bottom sampling methods were compared, regarding their sampling efficiency and the damage they may cause to macrobenthic and meiobenthic organisms. Two of the sampling methods examined are typically employed for the study of hard bottom substrates (manual collection, airlift device), while the third involves a newly constructed sampler (MANOSS – Manual Operated Suction Sampler). All three sampling methods were tested at 12 m depth on a hard bottom substrate with algal coverage dominated by Cystoseira spp. No overall significant differences were observed between the sampling efficiency and the damage caused by the three sampling methods regarding the macrofaunal assemblages, with the exception of the MANOSS method which collected more species than the manual method. In addition, significant differences were observed in the collecting performance for the meiobenthic assemblages, presenting significantly higher densities of meiofauna sampled by the MANOSS compared with the manual collection method, while the airlift device presented an intermediate efficiency. However, taking into account other factors such as cost, ease of use and the scope of each study, none of the methods clearly outperforms the others.

Diversity and Seasonal Fluctuations of Arthropod Fauna in Bangladesh Deepwater Rice

An intensive study of the diversity of arthropod fauna in Bangladesh deepwater rice ecosystem from 1977 to 1980 revealed: 139 phytophages, 75 predators, 75 parasitoids and 44 scavengers identified to species level. Adding those forms identified to family/subfamily brought the total to 375 species. Insecta comprised 354 species belonging to more than 100 families. This is a conservative estimate since the main sampling methods used, sweepnetting and the rearing of parasitoids, is fairly effective for mid- and upper canopy forms, but is not effective for collecting fauna in the benthos, neuston and lower plant canopy for which a suction sampler is necessary.There was a marked seasonal fluctuation in numbers and composition of the fauna due mainly to the nature of the deepwater rice plant and the annual flooding pattern. The preflood period was conducive to moderate buildups of some canopy-living insects. In the flooding period the numbers of many arthropods crashed precipitously and never recovered (eg leafhoppers and planthoppers). Those forms adapted to deep flooding continued at moderate levels (eg acridids, green leafhopper), while a few arthropods were able to increase their numbers (eg tettigonids, yellow stem borer and spiders). Spiders, the most abundant predator group, were numerous at all times even during deep flooding and they probably limited the numbers of leafhoppers, planthoppers and some other pests. In addition, 75 parasitoids formed part of the faunal community and attacked many phytophages.DOI: http://dx.doi.org/10.3329/brj.v17i1-2.20903Bangladesh Rice j. 2013, 17(1&2): 75-104

Οικολογικά πρότυπα και συμβολή στη μελέτη της γενετικής διαφοροποίησης των πολυχαιτών σε περιοχές σκληρού υποστρώματος στην Κρήτη

Στην παρούσα διδακτορική διατριβή μελετώνται οι οργανισμικές συνευρέσεις της ταξοκοινωνίας των Πολυχαίτων αλλά και η πληθυσμιακή γενετική δομή ενός από τα πλέον άφθονα είδη, σε δύο περιοχές σκληρού υποστρώματος. Δύο διαδοχικές δειγματοληπτικές προσπάθειες πραγματοποιήθηκαν τα έτη 2007-2008 στις περιοχές Αλυκές και Ελούντα (βόρεια κεντρική και ανατολική ακτή της Κρήτης αντίστοιχα) με βάση το πρωτόκολλο του προγράμματος NaGISA. Σύμφωνα με το συγκεκριμένο πρωτόκολλο από κάθε περιοχή πέντε επαναληπτικά δείγματα συλλέγονται από τρεις περιοχές της μεσοπαραλιακής και από πέντε βάθη της υποπαραλιακής ζώνης. Η συλλογή των οργανισμών πραγματοποιήθηκε με την βοήθεια υποθαλάσσιας αναρροφητικής συσκευής. Από τα προβλήματα στη χρήση της, προέκυψε η ανάγκη κατασκευής νέου δειγματοληπτικού εργαλείου. Ο νέος δειγματολήπτης που κατασκευάστηκε, ονομάζεται ManOSS (Manually Operated Suction Sampler) και συνδυάζει χαρακτηριστικά από τους δειγματολήπτες τύπου ΣΑΝΑ (συσκευή αναρρόφησης με αέρα) και ΥΔΑ (υδραυλική αντλία). Τα πρώτα αποτελέσματα έδειξαν ότι ο ManOSS εμφανίζει αξιοσημείωτα πλεονεκτήματα σε σχέση με τα έως τώρα δειγματοληπτικά εργαλεία. Από τις αναλύσεις στο βιοκοινοτικό επίπεδο προέκυψε ότι οι δύο περιοχές δειγματοληψίας είναι δυνατόν να θεωρηθούν αντιπροσωπευτικές της Μεσογείου, μόνο κάτω από ορισμένες προϋποθέσεις. Παράλληλα με τη βοήθεια των δεικτών της ταξινομικής διακριτότητας (μέσος όρος και μεταβλητότητα), βρέθηκε ότι τα πρότυπα κατανομής των ειδών με βάση την πιο άφθονη οικογένεια της υποπαραλιακής ζώνης (Syllidae), είναι δυνατόν να θεωρηθούν τυχαία μόνο στα μικρά επίπεδα χωρικής παρατήρησης (επαναληπτικό δείγμα και δειγματοληπτικό βάθος). Η ταυτότητα των δεδομένων αποτέλεσε το μόνο παράγοντα που βρέθηκε να επηρεάζει τα πρότυπα κατανομής της πολυχαιτοπανίδας των μεσοπαραλιακών περιοχών της Μεσογείου. Ουσιαστικά, ο παράγοντας αυτός περικλείει ένα σύνολο άλλων παραγόντων, που επηρεάζουν όλη τη δομή της έρευνας από τα αρχικά επιστημονικά ερωτήματα μέχρι την ερμηνεία των αποτελεσμάτων και τα εξαγόμενα συμπεράσματα. Για την πληθυσμιακή γενετική ανάλυση εξετάστηκαν 80 άτομα του είδους Hermodice carunculata (40 από κάθε περιοχή). Βρέθηκαν σημαντικές διαφορές στη κατανομή των απλοτύπων, αφού από τους συνολικά 15 απλότυπους μόνο ένας εμφανίζεται κοινός, ενώ οι υπόλοιποι κατανέμονται ισομερώς στις δύο περιοχές. Τέλος, παρατηρήθηκε ότι ο δείκτης ποικιλότητας κίνησης, bw, ο οποίος υπολογίστηκε με βάση την ταξοκοινωνία των Πολυχαίτων από τις δύο περιοχές δειγματοληψίας, και ο γενετικός δείκτης FST , ο οποίος υπολογίστηκε με βάση τη συχνότητα εμφάνισης των αλληλόμορφων του είδους H. carunculata στις δύο περιοχές μελέτης, λαμβάνουν σχεδόν ταυτόσημες τιμές. Το εύρημα αυτό είναι δυνατόν να αποτελέσει μια πρώτη ένδειξη για τη συσχέτιση του βαθμού διαφοροποίησης όπως αυτή παράγεται από το επίπεδο της δια - πληθυσμιακή γενετική δομή ενός είδους και της ταξοκοινωνίας.

Melitoid amhipods of the genera Ceradocus Costa, 1853 and Victoriopisa Karaman and Barnard, 1979 (Crustacea: Amphipoda: Maeridae) from the South China Sea, Malaysia

Two new species of Melitoid amphipods from Pulau Perhentian Besar and Pulau Tinggi, east coast of Peninsular Malaysia were described and illustrated. Specimens were collected by means of an airlift suction sampler at seagrass areas of the two islands. Ceradocus mizani sp. nov. found commonly at seagrass areas of Malaysian waters, can be readily distinguished from any other known Ceradocus species by a set of distinct characters based on the asymmetrical male gnathopod 2; sculpturing on the palm of the larger gnathopod 2; serrated pleonal epimeron 1–3; and multidentate dorsal pleonites and urosomites with 11 spines on urosomite 1 and 6 spines on urosomite 2. Victoriopisa tinggiensis sp. nov. on the other hand is characterized by its prolonged lateral cephalic lobe; the presence of an anteroventral notch on the head; weakly developed eyes; and pereopod 7 basis with intermediate lobation. This would be the first record of the genus Ceradocus and Victoriopisa from the waters of Peninsular Malaysia. Discovery of these two new species represents an ongoing and continuous effort on amphipod taxonomical studies here in Malaysia.

A new species of Malacoceros (Polychaeta: Spionidae) from Kick'em Jenny, a hydrothermally active submarine volcano in the Lesser Antilles Arc

A new spionid polychaete, Malacoceros jennicus, is described from the crater of a hydrothermally active submarine volcano near Grenada in the Caribbean, Lesser Antilles Arc region. The new species is characterized by having prominent lateral frontal horns on the prostomium, paired eye spots, neurosetae that include simple capillaries, inferior sabre setae, numerous bidentate hooded hooks, and a pygidium bearing four digitiform anal cirri surrounding the anus. Worms were collected in regions of diffuse venting with a suction sampler deployed on an ROV. Specimens representing a range of sizes including sexually mature and reproductive individuals containing eggs and sperm were found. Stable isotope analysis of 13C and 15N indicate mixed feeding on photosynthetic and hydrothermal vent source material.

Small-scale variation within a Modiolus modiolus (Mollusca: Bivalvia) reef in the Irish Sea. III. Crevice, sediment infauna and epifauna from targeted cores

Beds of Modiolus modiolus, in areas of moderate to strong tidal currents, develop into reefs with a relief of wave like undulations 0.09–0.45 m in amplitude and length scales of 6–18 m. Cores taken by diver operated suction sampler were targeted at positions on the ridges and troughs of a reef, in the Irish Sea off north-west Wales, allowing the fauna to be compared between adjoining ridges and troughs. Sessile epifauna was mostly attached to the larger mussels clumped together on the ridges. The crevice fauna and infauna were also nearly three times more abundant on the ridges, but the lists of species were similar from the two sub-habitats. Species richness was higher on the ridges, however, diversity and evenness measures were similar for ridges and trough samples. The Modiolus sub-habitats were found to be distinct from other macrofaunal assemblages in the wider southern Irish Sea. Deposition of faecal pellets in the spatially complex habitat amongst the mussels provided conditions suitable for an infauna more typical of inshore muddy sands enriched by organic matter. The scale of the ridge and trough morphology may increase variability between replicates when grabs are used remotely to sample this type of biogenic feature.

Multidimensional Water Flow in Variably Saturated Soils

Chapters 4 and 5 dealt with one-dimensional rectilinear flow, with and without the effect of gravity. Now the focus is on multidimensional flow. We will refer to two- and three-dimensional flow based on the number of Cartesian coordinates necessary to describe the problem. For this convention, a point source emitting a volume of water per unit time results in a three-dimensional problem even if it can be described with a single spherical coordinate. Similarly, a line source would be two-dimensional even if it could be described with a single radial coordinate. A problem with axial symmetry will be termed a three-dimensional problem even when only a depth and radius are needed to describe the geometry. The pressure at a point source is undefined. But more generally, three-dimensional point sources refer to flow from finite-sized sources into a larger soil domain, such as infiltration from a small surface pond into the soil. Often, the soil domain can be taken as infinite in one or more directions. Also, a point sink can occur with flow to a sump or to a suction sampler. In two dimensions, the same types of example can be given, but we will refer to them as line sources or sinks. Practical interest in point sources includes analyses of surface or subsurface leaks and of trickle (drip) irrigation. The desirability of determining soil properties in situ has provided the impetus for a rigorous analysis of disctension and borehole infiltrometers. Also, environmental monitoring with suction cups or candles, pan lysimeters, and wicking devices all include convergent or divergent flow in multidimensions. There are some conceptual differences between line and point sources and one-dimensional sources. For discussion, consider water supplied at a constant matric potential into drier surroundings. For a one-dimensional source, the corresponding physical problem includes a planar source over an area large enough for “edge” effects to be negligible. For two dimensions, the source might be a long horizontal cylinder or a furrow of finite depth from which water flows. For three dimensions, the source could be a small orifice providing water at a finite rate or a small, shallow pond on the soil surface.