Spatial and temporal variation of the fatty acid composition of Patella spp. (Gastropoda: Prosobranchia) soft bodies and gonads

To clarify the occurrence of nonmethylene-interrupted (NMI) FA in the marine bivalve Megangulus zyonoensis, methyl esters of unsaturated FA were fractionated according to the degree of their unsaturation by using argentation TLC. Their structures were elucidated by using GC-MS of their FAME and 2-alkenyl-4,4-dimethyloxazoline derivatives. Seventy-two unsaturated FA, including the novel 7,15-21 and 20:4n-1, were identified. The unusual tetraenoic acids 20:4n-4, 20:4n-1, 21:4n-6, and 21:4n-5 were found in M. zyonoensis. This bivalve was extremely rich in the positional isomers of 19:1, 20:2, and 20:3. The distribution of NMI and positional isomers of unusual FA in the bivalve tissues was also discussed.

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“…soft bodies and gonads. These FA were present in very low amounts (below 1%) and were probably linked with the limpet's diet (25).…”

Section: Discussionmentioning

confidence: 99%

Identification of minor fatty acids and various nonmethylene‐interrupted diene isomers in mantle, muscle, and viscera of the marine bivalve Megangulus zyonoensis

Kawashima

Ohnishi

2004

Lipids

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“…Thus, the onset of oxidative stress during early spring affects both, the water and lipid phases of the digestive gland tissue. It is important to point out, as it was reported by Brazao et al (2003), that the environmental conditions to which the limpets are submitted in particular the diet, affect their lipid composition, that could alter lipid radical generation. Seasonal changes not only affect ROS generation but also reactive nitrogen species (RNS) formation as well, since the NO content also increased in summer in comparison to winter in limpet digestive glands.…”

Section: Oxidative Stress Index In Subantarctic Limpetsmentioning

confidence: 99%

The effect of seasonality on oxidative metabolism in Nacella (Patinigera) magellanica

Malanga

Estevez

Calvo

et al. 2007

Comparative Biochemistry and Physiology Part A: Molecular &

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We studied the seasonal variation on aerobic metabolism and the response of oxidative stress parameters in the digestive glands of the subpolar limpet Nacella (P.) magellanica. Sampling was carried out from July (winter) 2002 to July 2003 in Beagle Channel, Tierra del Fuego, Argentina. Whole animal respiration rates increased in early spring as the animals spawned and remained elevated throughout summer and fall (winter: 0.09 ± 0.02. Oxidative stress was assessed at the hydrophilic level as the ascorbyl radical content / ascorbate content ratio (A U / AH − ). The A U / AH − ratio showed minimum values in winter (3.7 ± 0.2 10 − 5 AU) and increased in summer (18 ± 5 10 − 5 AU). A similar pattern was observed for lipid radical content (122 ± 29 pmol mg − 1 fresh mass [FW] in winter and 314 ± 45 pmol mg − 1 FW in summer), iron content (0.99 ± 0.07 and 2.7 ± 0.6 nmol mg − 1 FW in winter and summer, respectively) and catalase activity (2.9 ± 0.2 and 7 ± 1 U mgFW in winter and summer, respectively). Since nitrogen derived radicals are thought to be critically involved in oxidative metabolism in cells, nitric oxide content was measured and a significant difference in the content of the Fe-MGD-NO adduct in digestive glands from winter and summer animals was observed. Together, the data indicate that both oxygen and nitrogen radical generation rates in N. (P.) magellanica are strongly dependent on season.

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“…When small prey are not available, it may no longer be optimal to spend the energy on a potentially fruitless attack on a large prey item, and this could explain why the numbers of large prey eaten in the Stage 1 trials were smaller. Alternatively, small limpets may not be the preferred prey based on their energy content since for instance, the gonadal tissue (high in lipid content; see Brazão et al 2003) would be smaller in 15 to 25 mm P. vulgata than for large individuals (> 30 mm; Blackmore 1969). Hence, N. puber of most sizes foraging on the shore would be likely to choose 15 to 20 mm size limpets since these are common and are well within their mechanical ability.…”

Section: Discussionmentioning

confidence: 99%

Preferential feeding by the crab Necora puber on differing sizes of the intertidal limpet Patella vulgata

Silva¹,

Hawkins²,

Clarke³

et al. 2010

Mar. Ecol. Prog. Ser.

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The crab Necora puber L. is a common predator of limpets, the major grazer on rocky shores in Northern Europe. Information on interactions between crabs and their limpet prey is limited, extending mainly to limpet defensive and predator offensive tactics, while the importance of prey size on the outcome of such interactions remains largely unknown. Here, a laboratory approach was used to test for preference in feeding habits. Predation by N. puber with cheliped height 3 to 27 mm (carapace width [CW]: 16 to 77 mm) was examined on Patella vulgata with shell length 5 to 60 mm. Predator size (10,(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and 21-25 mm cheliped height) and prey size (5-10, 15-20, 25-30 and 35-40 mm shell length) were examined, with 2 replicate tests for each predator-prey size combination. Crabs >10 mm in cheliped height (35 mm CW) predominantly crushed the shell of limpets <10 mm, while in the remaining combinations of predator and prey sizes, crabs prised limpets from the substratum. Size of limpet shell (vulnerability to crushing force) and resistance to leverage force were both important factors influencing the outcomes of crab-limpet interactions. For the largest crab tested (27 mm cheliped height; 77 mm CW), there was a size refuge for limpets > 41 mm in shell length. Field observations showed that the majority (94%) of limpets present in the intertidal zone are of a size that is vulnerable to predation by N. puber. For all sizes of crab examined, there were clear preferences for limpets smaller than the maximum size that the crabs were actually able to consume. Intriguingly, however, the preference experiment showed that, when given a choice, crabs consistently consumed proportionately more limpets of a larger size-class than when presented only with a single size-class at a time. Although further in situ studies are necessary, the present study indicates that size-selective predation by N. puber and other crabs may have an important influence on limpet population structure. KEY WORDS: Handling behaviour · Intertidal · Size refuge · Size preferenceResale or republication not permitted without written consent of the publisher

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Spatial and temporal variation of the fatty acid composition of Patella spp. (Gastropoda: Prosobranchia) soft bodies and gonads

Cited by 39 publications

References 27 publications

Identification of minor fatty acids and various nonmethylene‐interrupted diene isomers in mantle, muscle, and viscera of the marine bivalve Megangulus zyonoensis

Identification of minor fatty acids and various nonmethylene‐interrupted diene isomers in mantle, muscle, and viscera of the marine bivalve Megangulus zyonoensis

The effect of seasonality on oxidative metabolism in Nacella (Patinigera) magellanica

Preferential feeding by the crab Necora puber on differing sizes of the intertidal limpet Patella vulgata

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