A new species of lugworm: <i>Arenicola defodiens</i> sp. nov.

Cadman, P.S.; Nelson-Smith, A.

doi:10.1017/s0025315400032744

Cited by 24 publications

(17 citation statements)

References 9 publications

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“…The short residence time of the ingested sand in the gut (Hüttel 1990, Chen & Mayer 1999 makes it unlikely that internal fermentation (as in ruminants) occurs; rather, the lugworm-bioturbated burrow/sand-substrate system may act as an external rumen in which bacteria are cultivated, ingested and digested -a process of food enhancement referred to as gardening (Plante & Mayer 1994. Feeding at depth on anaerobic sediment is most characteristic of A. defodiens (Cadman & Nelson-Smith 1993) but it is also observed in A. marina when feeding on sediments rich in organic material in nature (Cadée 1976) and in the laboratory (Rijken 1979), and is routinely observed in commercially farmed populations 1 (S. Craig unpubl. data, P. J. W. Olive pers.…”

Section: Resale or Republication Not Permitted Without Written Consenmentioning

confidence: 99%

“…The caudate lugworms Arenicola marina (L.) and A. defodiens Cadman and Nelson-Smith, 1993 are frequently the biomass-dominant species on the intertidal beaches of western Europe (Cadée 1976, Beukema & de Vlas 1979, Olive 1993. The basic feeding method is well established, but the precise nature of their dietary structure remains problematical.…”

Section: Introductionmentioning

confidence: 99%

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Net gain of long-chain polyunsaturated fatty acids (PUFA) in a lugworm Arenicola marina bioturbated mesocosm

Olive

Duangchinda²,

Ashforth³

et al. 2009

Mar. Ecol. Prog. Ser.

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A net gain in long-chain polyunsaturated fatty acids (PUFA) occurs in Arenicola marina bioturbated mesocosms in the light and dark when brewery yeast is the only food. Fatty acid profiles were determined by GC-MS and quantified for system units. Bacterial fatty acid biosynthesis is indicated by accumulation of the bacterial fatty acids anteiso 14:0, iso 15:0, iso 16:0, anteiso 16:0, iso 17:0, C16:1n-7 and C18:1n-7 (cis-vaccenic acid). De novo production of longer chain PUFA within the worm tissues is implicated by a chain elongation converting linoleic acid (C18:2n-6) to C20:2n-6 and subsequent desaturation, resulting in a gain of arachidonic acid (C20:4n-6) and eicosapentaenoic acid (C20:5n-3) via the intermediary C20:3n-6. To test for the presence of PUFA-synthesising bacteria in system units, 495 cloned 16S rDNA fragments were compared with the databases and degenerate PCR primers were designed for the ketoacyl acyl carrier protein synthase gene highly conserved in the polyketide synthase region of known PUFA-synthesising Gammaproteobacteria. Gammaproteobacteria related to known PUFA producers were not abundant (<1% of clones) and PCR primers, whose specificity was confirmed by conspecific amplification of DNA product from genomic DNA of Shewenella frigidimarina 12253 T and Colwellia psychrethraea 8813 T , did not amplify product from mesocosm DNA samples. PUFA production is therefore primarily due to processes within the lugworm A. marina. Biosynthesis by invertebrates may be significant in benthic ecosystems and their culture has the potential to contribute to non-fishery sources of essential fatty acids required for aquaculture feeds.KEY WORDS: Fatty acid biosynthesis · Elongase · PUFA · Polychaeta · Marine food web · Arenicola marina · Aquaculture nutrition · Aquaculture feeds Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 387: [223][224][225][226][227][228][229][230][231][232][233][234][235][236][237][238][239] 2009 head shaft) lying above the feeding pocket and contribute to the diet, but algae are not utilised effectively (Rijken 1979) and the presence of cellulases has not been conclusively demonstrated (Longbottom 1970, nor since). On the other hand feeding on bacteria associated with enriched sand is considered likely. The short residence time of the ingested sand in the gut (Hüttel 1990, Chen & Mayer 1999 makes it unlikely that internal fermentation (as in ruminants) occurs; rather, the lugworm-bioturbated burrow/sand-substrate system may act as an external rumen in which bacteria are cultivated, ingested and digested -a process of food enhancement referred to as gardening (Plante & Mayer 1994. Feeding at depth on anaerobic sediment is most characteristic of A. defodiens (Cadman & Nelson-Smith 1993) but it is also observed in A. marina when feeding on sediments rich in organic material in nature (Cadée 1976) and in the laboratory (Rijken 1979), and is routinely observed in commercially farmed populations 1 (S. Craig unpubl. data, P. J. W...

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Section: Resale or Republication Not Permitted Without Written Consenmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Net gain of long-chain polyunsaturated fatty acids (PUFA) in a lugworm Arenicola marina bioturbated mesocosm

Olive

Duangchinda²,

Ashforth³

et al. 2009

Mar. Ecol. Prog. Ser.

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“…The list of genera analyzed genetically is now longer, and additions include Polydora (Mustaquim, 1988;Manchenko & Radashevsky, 1993, Capitella (Baoling et al, 1991;Gamen-ick et al, 1998), Marenzellaria (Bastrop et al, 1998), Arenicola (Cadman & Nelson-Smith, 1993), Eulalia (Bonse et al, 1996), Petitia (Van Soosten et al, 1998), Nereis (Rodriguez-Trelles et al, 1996), Nerilla (Schmidt & Westheide, 1997), and Hediste (Fong & Garthwaite, 1994;Abbiati & Maltagliati, 1996;Rohner et al, 1997;Sato & Masuda, 1997). Nevertheless, genetic information remains scanty, even for the genus Capitella, despite the highly influential early paper by Grassle and Grassle (1976) and the importance of this group for pollution studies.…”

Section: Polychaetamentioning

confidence: 99%

Molecular genetic analyses of species boundaries in the sea

2000

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The tools of molecular genetics have enormous potential for clarifying the nature and age of species boundaries in marine organisms. Below I summarize the genetic implications of various species concepts, and review the results of recent molecular genetic analyses of species boundaries in marine microbes, plants, invertebrates and vertebrates. Excessive lumping, rather than excessive splitting, characterizes the current systematic situation in many groups. Morphologically similar species are often quite distinct genetically, suggesting that conservative systematic traditions or morphological stasis may be involved. Some reproductively isolated taxa exhibit only small levels of genetic differentiation, however. In these cases, large population sizes, slow rates of molecular evolution, and relatively recent origins may contribute to the difficulty in finding fixed genetic markers associated with barriers to gene exchange. The extent to which hybridization blurs species boundaries of marine organisms remains a subject of real disagreement in some groups (e.g. corals). The ages of recently diverged species are largely unknown; many appear to be older than 3 million years, but snails and fishes provide several examples of more recent divergences. Increasingly sophisticated genetic analyses make it easier to distinguish allopatric taxa, but criteria for recognition at the species level are highly inconsistent across studies. Future molecular genetic analyses should help to resolve many of these issues, particularly if coupled with other biological and paleontological approaches.

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“…It was suggested that this may represent a discrete species. Cadman & Nelson-Smith (1990) examined phenotypically different populations of Arenicola marina and discovered an I value of 0.2717; a taxonomic revision of the species followed (Cadman & Nelson-Smith 1993). Debate persists about the relationship between genetic variation and speciation and is fuelled by discoveries of groups in which speciation proceeds with little genetic differentiation (African lake cichlids and birds; Thorpe 1983, Meyer et al 1990).…”

Section: Genetic Variabilitymentioning

confidence: 99%

Evidence for poecilogony in Pygospio elegans (Polychaeta:Spionidae)

Morgan¹,

Rogers²,

Paterson³

et al. 1999

Mar. Ecol. Prog. Ser.

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The spionid polychaete Pygospio elegans displays more than one developmental mode. Larvae may develop directly, ingesting nurse eggs while brooded in capsules within the parental tube. or they may hatch early to feed in the plankton before settling. Asexual reproduction by architomic fragmentation also occurs. Geographically separated populations of P. elegans often display different life histories. Such a variable life history within a single species may be interpreted either as evidence of sibling speciation or of reproductive flexibility (poecilogony). Four populations from the English Channel were found to demonstrate differing life histories and were examined for morphological and genetic variability to determine whether P, elegans is in fact a cryptic species complex. Significant but minor inter-population polymorphisms were found in the distribution of branchiae and the extent of spoonlike hooded hooks. These externally polymorphic characters did not vary with relation to life history, and variation fell within the reported range for this species. Cellulose acetate electrophoresis was used to examine 10 allozyrne loci, 5 of which were polymorphic. Overall, observed heterozygosity (H, = 0.161) was lower than that expected under Hardy-Weinberg equilibrium (H,= 0.228). Significant heterozygote deficiencies, detected at the Est' and Xdh' loci in all populations (except Xdh' at Ryde Sand, Isle of Wight, UK), are discussed. F-statistics were used to examine patterns of genetic structuring anlong both separate and pooled populations. Fn values at all polymorphic loci indicated a significant level of genetic differentiation between populations, most probably related to isolation by geographic distance. No direct relationship between life history and genetic structure could be detected. Overall genetic identity among the 4 populations was high (I = 0.977 to 0.992). Overall, populations displaying larval brooding did not appear to be reproductively isolated from populations displaying a fully planktonic larval mode. Present data support the hypothesis that P. elegans is poecilogonous.

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A new species of lugworm: Arenicola defodiens sp. nov.

Cited by 24 publications

References 9 publications

Net gain of long-chain polyunsaturated fatty acids (PUFA) in a lugworm Arenicola marina bioturbated mesocosm

Net gain of long-chain polyunsaturated fatty acids (PUFA) in a lugworm Arenicola marina bioturbated mesocosm

Molecular genetic analyses of species boundaries in the sea

Evidence for poecilogony in Pygospio elegans (Polychaeta:Spionidae)

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