Lacuna vincta (Mollusca, Neotaenioglossa) herbivory on juvenile and adult Nereocystis luetkeana (Heterokontophyta, Laminariales)

Hydrobiologia ◽  
2007 ◽  
Vol 583 (1) ◽  
pp. 107-118 ◽  
Author(s):  
Heloise Chenelot ◽  
Brenda Konar
Keyword(s):  
Lacuna Vincta ◽  
Nereocystis Luetkeana

scholarly journals Factors influencing recruitment and appearance of bull kelp, Nereocystis luetkeana (phylum Ochrophyta)

2018 ◽  
Vol 55 (1) ◽  
pp. 236-244 ◽  
Author(s):  
Katie A. Dobkowski ◽  
K. Darby Flanagan ◽  
Jessica R. Nordstrom
Keyword(s):  
Factors Influencing ◽  
Nereocystis Luetkeana

Seasonal photosynthetic performance of Nereocystis luetkeana

1984 ◽  
Vol 62 (4) ◽  
pp. 664-670 ◽  
Author(s):  
W. N. Wheeler ◽  
R. G. Smith ◽  
L. M. Srivastava
Keyword(s):  
Flux Density ◽  
Late Summer ◽  
Photosynthetic Performance ◽  
Initial Slope ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Rates ◽  
Chl A ◽  
Light Intensities ◽  
Nereocystis Luetkeana

Pigment levels, photosynthetic performance, and tissue nitrogen levels of three age-class blade disks of Nereocystis luetkeana were followed over one complete and two partial growth seasons. Chlorophyll (chl) a, fucoxanthin, and chlorophyll c all showed high levels in fall–winter and low levels in late summer. The molar ratios also varied with much higher fucoxanthin: chl a and chl c: chl a ratios in early spring than in late summer–fall. Plots of maximum photosynthetic rates (Pmax) at saturating light intensities and initial slopes (α) derived from photosynthetic rates at subsaturating light intensities also showed seasonal variations, with maxima in August and September and minima in April. The saturating light irradiance, IR, also showed a maximum in late summer and a minimum in winter. Tissue nitrate levels were high in winter, declined to near zero levels in May–August, and increased again in fall–winter. Amino acids and total N followed a similar pattern. The older tissues farthest from the bulb had higher Pmax and pigment levels as well as internal nitrate levels than young proximal tissues. Environmental data on sea-water nitrate, photon flux density, and temperature and data on mannitol and total C are presented. It appears that there is a significant negative correlation between photon flux density and initial slope of photosynthesis and between Pmax and temperature below 15 °C. At temperatures above 15 °C, internal N concentrations, which in turn are governed by the ambient nitrate concentration, appear to become limiting. Pigment levels, especially chlorophyll a, showed a direct correlation with ambient nitrate. These data are discussed in relation to the possible biennial nature and growth strategy of Nereocystis.

scholarly journals Carbon Monoxide a Respiration Product of Nereocystis Luetkeana

1920 ◽  
Vol 70 (3) ◽  
pp. 230-239 ◽  
Author(s):  
Seth C. Langdon ◽  
W. R. Gailey
Keyword(s):  
Carbon Monoxide ◽  
Nereocystis Luetkeana

Grazing by the gastropod, Lacuna vincta, in the lower intertidal area at Musquash Head, New Brunswick, Canada

1983 ◽  
Vol 63 (3) ◽  
pp. 725-736 ◽  
Author(s):  
Martin L. H. Thomas ◽  
Frederick H. Page
Keyword(s):  
New Brunswick ◽  
Egg Production ◽  
Algal Species ◽  
Egg Mass ◽  
Intertidal Area ◽  
Mass Distributions ◽  
Lacuna Vincta ◽  
Egg Deposition ◽  
Large Numbers ◽  
The Impact

Lacuna vincta appeared at Musquash Head, New Brunswick, in large numbers from June to August 1981 principally on lower midlittoral and infralittoral fringe Fucus edentatus. The population reached a mean maximum of 280/m2 in June; by mid September the animals had disappeared. The L. vincta grazed heavily and deposited egg masses on Fucus edentatus but little on other species. All fine and filamentous and encrusting algal species and rock were avoided for egg deposition. Egg mass abundance peaked with the population in June with a mean of 180/m2. Mean egg production in June was 83000/m2.Both snail and egg mass distributions were correlated with the percentage cover of F. edentatus, reaching a maximum at 40–75 cm above mean low tide level.The snails ranged in length from 2–7 mm, consisting of three cohorts from different larval settlements. Growth was rapid in July averaging 0·6 mm/month slowing later.The food plant Fucus edentatus showed a heavy impact of the herbivore. Weight reductions attributable to grazing rose from 56 % in June to 79 % in August and grazed plants tended to thicken rather than elongate with growth. Grazing removed about 79 % of the net production of F. edentatus which averaged 61 g dry wt/m2/day. The impact of the L. vincta population on F. edentatus seems extraordinarily severe.

Seasonal Changes in Population Density and Vertical Distribution of prosobranch veligers in offshore Plankton at Plymouth

1973 ◽  
Vol 53 (3) ◽  
pp. 471-492 ◽  
Author(s):  
Vera Fretter ◽  
D. Shale
Keyword(s):  
Population Density ◽  
Vertical Distribution ◽  
Seasonal Changes ◽  
Littorina Littorea ◽  
Ageing Population ◽  
Age Composition ◽  
Number Of Species ◽  
Lacuna Vincta ◽  
Nassarius Reticulatus ◽  
Inshore Waters

Vertical and horizontal hauls were taken at approximately fortnightly intervals from April 1969 to April 1970 at L 3 (lat. 40° 17.7′ N, long. 4° 11.2′ W) and L 4 (lat. 50° 15′ N, long. 4° 12.5 W). Thirty-two species of prosobranch veliger were present at L 35 these larvae were not as numerous at L 4 and only 26 species were recorded. The number of species was highest in the summer: the number of veligers was highest in February. After mid October both the number of species and the abundance of veligers decreased rapidly and remained low until early February. Veligers of some species occurred later at L 3 and L 4 than in more inshore waters and these were probably individuals carried beyond tidal influences which would normally lead to settlement on the shore. They included Lacuna vincta, Littorina littorea and L. neritoides.Veligers of all ages were found at all depths. At their time of greatest abundance veligers of many species occurred maximally at 5 or 10 m, with a variable decrease towards greater depths and a sudden one towards the surface. This distribution later changed giving a proportionally greater number at greater depth. When numbers were low the larvae scattered through the water column with little or no indication of a preferred depth. An examination of the age composition of veligers of rissoids, Natica alderi, Nassarius reticulatus and Philbertia linearis from certain catches showed that the surface accumulation at the time of abundance was composed of a high percentage of young veligers: in an ageing population there was a higher percentage of larvae, especially the older ones, at greater depths, except for Nassarius reticulatus which consistently showed maximal numbers above 10 m until the larvae became scarce.

GROWTH OF BLADES OF NEREOCYSTIS LUETKEANA (PHAEOPHYTA) IN DARKNESS

1987 ◽  
Vol 23 (3) ◽  
pp. 464-469 ◽  
Author(s):  
Joanna M. Kain (Jones) ◽  
Trevor A. Norton ◽  
Ann E. Montegut
Keyword(s):  
Nereocystis Luetkeana

Metamorphic Changes in the Velar Musculature, Head and Shell of some Prosobranch Veligers

1972 ◽  
Vol 52 (1) ◽  
pp. 161-177 ◽  
Author(s):  
Vera Fretter
Keyword(s):  
Nerve Ring ◽  
Retractor Muscle ◽  
Dorsal Part ◽  
Intimate Contact ◽  
Lower Lip ◽  
Lacuna Vincta ◽  
Area Of Origin

The velum of Lacuna vincta (Montagu) and Nassarius incrassatus (Ström) is retracted into the shell by 2 dorsal and 2 ventral groups of muscles, bilaterally arranged, which are components of the larval retractor muscle. Each dorsal group passes forward from its area of origin on the shell to the dorsal part of the head where some fibres insert and adjacent ones enter the velar fold. The velum is bilobed in Lacuna and the muscles radiate through the dorsal half of the lobe to insert on the anterior and posterior surfaces and ciliated edge, whereas Nassarius has 4 long velar lobes, 2 dorsal and 2 ventral, and the muscles form a median bundle from which fibres radiate to similar insertions. Each ventral group of muscles passes through the nerve ring lateral to the developing radular sac in Lacuna and to the developing proboscis in Nassarius, and muscles accompanying them insert on the sac and proboscis wall. Anterior to the ring some muscles insert on the lips and the buccal wall posterior to the oral sphincter and alongside attachments of muscles from the foot. The majority pass to the mentum, a median protuberance of the lower lip with non-vibratile cilia, where right and left ventral cephalic retractors and muscles from the foot converge. The pedal muscles attach here and from this area muscles radiate to multiple insertions on the head and ventral half of the velum. This arrangement of the ventral muscles allows the increased angle of mobility required by the ventral areas of the velum in swimming and feeding and the intimate contact between velum and foot.

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