Study on the ecology of intertidal zones along the northern coast in Hangzhou Bay [China]. I. Survey of the soft bottom bethic fauna community

Accurate size measurements are fundamental in characterizing the population structure and secondary production of a species. The purpose of this study was to determine the best morphometric parameter to estimate the size of individuals of Capitella capitata (Fabricius, 1780). The morphometric analysis was applied to individuals collected in the intertidal zones of two beaches on the northern coast of the state of São Paulo, Brazil: São Francisco and Araçá. The following measurements were taken: the width and length (height) of the 4th, 5th and 7th setigers, and the length of the thoracic region (first nine setigers). The area and volume of these setigers were calculated and a linear regression analysis was applied to the data. The data were log-transformed to fit the allometric equation y = ax b into a straight line (log y = log a + b * log x). The measurements which best correlated with the thoracic length in individuals from both beaches were the length of setiger 5 (r² = 0.722; p<0.05 in São Francisco and r² = 0.795; p<0.05 in Araçá) and the area of setiger 7 (r² = 0.705; p<0.05 in São Francisco and r² = 0.634; p<0.05 in Araçá). According to these analyses, the length of setiger 5 and/or the area of setiger 7 are the best parameters to evaluate the growth of individuals of C. capitata.

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Chaetozone corona (Polychaeta, Cirratulidae) in the Bay of Biscay: a new alien species for the North-east Atlantic waters?

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315416000540 ◽

2016 ◽

Vol 97 (2) ◽

pp. 433-445 ◽

Cited By ~ 5

Author(s):

Vincent Le Garrec ◽

Jacques Grall ◽

Claire Chevalier ◽

Benjamin Guyonnet ◽

Jérôme Jourde ◽

...

Keyword(s):

Environmental Factors ◽

Northern Coast ◽

Bay Of Biscay ◽

Soft Bottom ◽

East Atlantic ◽

North East ◽

The North ◽

Vectors Of Introduction ◽

Iroise Sea ◽

First Time

The cirratulid species Chaetozone corona is reported for the first time from the North-east Atlantic waters. Several specimens were collected during oceanographic surveys between 1996 and 2015 from soft bottom habitats along the coasts of Brittany (Western France). This species, originally described from the coast of California, was recently recorded for the first time from the Mediterranean Sea. We hypothesize that this species could have been recently introduced to the Atlantic coasts of Europe and colonized the northern coast of Bay of Biscay from the Loire estuary to the Iroise Sea. We discuss the potential vectors of introduction and the main environmental factors that could explain its current distribution. An identification key to all the known North-east Atlantic species of Chaetozone is given.

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Spatial variability of larval parasites harboured by two crab species in an estuarine environment in Argentina

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315415000594 ◽

2015 ◽

pp. 1-5

Author(s):

Agustina Mendez Casariego ◽

Matias Merlo ◽

Jorge Etchegoin

Keyword(s):

Crab Species ◽

Soft Bottom ◽

Intertidal Zones ◽

Mean Intensity ◽

Neohelice Granulata ◽

Digenean Species ◽

Opposite Trend ◽

Species Overlap ◽

Spatial Differences ◽

Larval Parasites

Soft bottom intertidals of the Atlantic SW are dominated by the semi-terrestrial crabNeohelice granulataand the grapsid crabCyrtograpsus angulatus. They are similar in size butC. angulatusis mainly a subtidal species, whileN. granulatainhabits the intertidal zones, thus the two species overlap only during high tides in this area. Since these distribution differences between crab species across the Mar Chiquita Coastal lagoon may affect digenean infection success, the objective of this work is to describe the spatial differences in parasite infection levels and their selectivity on the host. To determine possible spatial differences in parasitism levels between sites and crab species across the lagoon, three areas dominated byN. granulatawere selected and adult crabs ofN. granulataandC. angulatuswere collected. Both crab species harboured metacercariae of the digeneansMicrophallus szidatiandMaritrema bonaerensis(Microphallidae), and cystacanths of the acanthocephalanProfilicollis chasmagnathi(Profilicollidae). Digenean species showed preferences between the two crabs.Maritrema bonaerensismean intensity was higher inN. granulatathan inC. angulatus, while the opposite trend was found forM. szidatiand could indicate some level of specificity. These results, nevertheless, depended on the study site. ForP. chasmagnathithe highest values of mean intensity depended more on the site than on the crab species. The values found here, compared with previous works from both crab species, suggest that besides the spatial heterogeneity, interspecific competition between parasites could explain the differences observed.

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Immune electron microscopy of haemocyanins from two southern african whelks

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081656 ◽

1978 ◽

Vol 36 (2) ◽

pp. 158-159

Author(s):

Linda M. Stannard ◽

Margaret Lennon

Keyword(s):

Electron Microscopy ◽

Electron Microscope ◽

Outer Ring ◽

Immune Electron Microscopy ◽

Intertidal Zones ◽

Central Belt ◽

Cape Peninsula ◽

Circular Contour

Burnupena cincta and Fusus verruculatus are two whelks which inhabit the intertidal zones of the Cape Peninsula shore. Their respiratory pigments, or haemocyanins, are morphologically similar in structure (Figs. 1 and 2) and appear in the electron microscope as short cylindrical rods about 34 nm in diameter and 36 nm high. Viewed side-on the molecules show regular banding suggesting a structure composed of six equidistant rings of sub-units. Occasionally the particles have the appearance of possessing a central “belt” in the position of the 3rd and 4th rows of sub-units. End-on views of the haemocyanin molecules show a circular contour with a dense outer ring and a less dense inner ring in which 10 definite sub-units may frequently be distinguished. A number of molecules display an extra central inner component which appears either as a diffuse plug or as a discrete ring-shaped core ± 8 nm in diameter.

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