91 research outputs found
Morphological evidence shows that not all Velesunioninae have smooth umbos
No full textMost species in the freshwater bivalve order Unionida (sensuCarter et al., 2011) display some form of shell sculpture during the early postlarval stage. These so-called ‘umbonal sculptures’, ‘beak sculptures’ or ‘rugae’ range from more or less regularly formed V- and zigzag-shapes to pseudoradial, pseudoconcentric and double-looped bars, and single-standing nodules (Modell, 1942, 1964; Watters, 1994; Zieritz, 2010). In some Unionida, this ornamentation may extend to mature ontogenetic stages (e.g. Hyriidae; Haas, 1969a, b; Watters, 1994). Others, however, are regarded as lacking sculptured umbos altogether. These include (1) the Mycetopodidae (according to descriptions by Modell, 1942, 1964; Haas, 1969a, b; Zieritz, 2010); (2) most Iridininae including Mutela rostrata (Rang, 1835), Pleiodon ovata (Swainson, 1823) and Pleiodon spekii (Woodward, 1859) (according to descriptions by Pilsbry & Bequaert, 1927; Zieritz, 2010); and (3) some Unionidae such as Actinonaias pectorosa (Conrad, 1834), Delphinonaias delphinulus (Morelet, 1849) and Pseudospatha tanganyicensis (Smith, 1880) (Zieritz, 2010). Finally, various authors, including Cotton & Gabriel (1932), Iredale (1934), Modell (1942, 1964), McMichael & Hiscock (1958) and Haas (1969a), stated that smooth umbos are also characteristic of all members of (4) the Velesunioninae, a subfamily of the Hyriidae endemic to the Australasian region (Walker et al., 2001; Walker, Jones & Klunzinger, 2013). Haas (1969b), on the other hand, described beak sculpture in the “subgenus Velesunio”—comprising four of the five currently recognized velesunionine genera (except Lortiella)—as “not strong, consisting of broken, nodulose ridges curving toward each other below, generally with smooth space between”. Unfortunately, no illustration of these sculptures has been made available by this or any other author to date.No Full Tex
Shell ecophenotype in the blue mussel (Mytilus edulis) determines the spatial pattern in foraging behaviour of an oystercatcher (Haematopus ostralegus) population
No full textWhen feeding on blue mussels (Mytilus edulis), oystercatchers (Haematopus ostralegus) either stab into the mollusc’s gaping valves or hammer through its dorsal or ventral shell. Whilst the selectivity of hammering and stabbing oystercatchers for specific prey morphologies has been well studied, the way in which the effects of environment on M. edulis morphology can in turn affect feeding methods of H. ostralegus is very poorly understood. Based on morphological analyses on randomly selected shells from three intertidal zones, this study failed to detect differences in morphology or distribution of dorsally and ventrally hammered shells but confirms the finding of previous authors that hammering oystercatchers select thinner mussels than stabbing birds. Additionally, we show that this difference in optimal prey morphology can lead to spatial patterns in oystercatcher feeding behaviour. Whilst at the low intertidal and higher mid intertidal zones, characterised by comparatively thick shells, most empty shells had apparently been stabbed, hammering was the dominant feeding behaviour at the lower mid intertidal zone, where shells were thinner. Preference of hammering birds for smaller mussels was not ubiquitous. Sagittal shell shape was predominantly influenced by allometric growth effects and had only minor effect on prey selection. All oystercatchers preferred less inflated mussels, with the degree of shell inflation gradually increasing with higher intertidal elevation. Our results illustrate the importance of small-scale patterns in prey ecophenotypes in determining the distribution and feeding dynamics of wading birds
Morphological evidence shows not all Velesunioninae have sculptured umbos
No full textMost species in the freshwater bivalve order Unionida (sensu Carter et al., 2011) display some form of shell sculpture during the early postlarval stage. These so-called ‘umbonal sculptures’, ‘beak sculptures’ or ‘rugae’ range from more or less regularly formed V- and zigzag-shapes to pseudoradial, pseudoconcentric and double-looped bars, and single-standing nodules (Modell, 1942, 1964; Watters, 1994; Zieritz, 2010). In some Unionida, this ornamentation may extend to mature ontogenetic stages (e.g. Hyriidae; Haas, 1969a, b; Watters, 1994). Others, however, are regarded as lacking sculptured umbos altogether. These include (1) the Mycetopodidae (according to descriptions by Modell, 1942, 1964; Haas, 1969a, b; Zieritz, 2010); (2) most Iridininae including Mutela rostrata (Rang, 1835), Pleiodon ovata (Swainson, 1823) and Pleiodon spekii (Woodward, 1859) (according to descriptions by Pilsbry & Bequaert, 1927; Zieritz, 2010); and (3) some Unionidae such as Actinonaias pectorosa (Conrad, 1834), Delphinonaias delphinulus (Morelet, 1849) and Pseudospatha tanganyicensis (Smith, 1880) (Zieritz, 2010). Finally, various authors, including Cotton & Gabriel (1932), Iredale (1934), Modell (1942, 1964), McMichael & Hiscock (1958) and Haas (1969a), stated that smooth umbos are also characteristic of all members of (4) the Velesunioninae, a subfamily of the Hyriidae endemic to the Australasian region (Walker et al., 2001; Walker, Jones & Klunzinger, 2013). Haas (1969b), on the other hand, described beak sculpture in the “subgenus Velesunio”—comprising four of the five currently recognized velesunionine genera (except Lortiella)—as “not strong, consisting of broken, nodulose ridges curving toward each other below, generally with smooth space between”. Unfortunately, no illustration of these sculptures has been made available by this or any other author to date
Fig. 4 in Hyriopsis panhai, a new species of freshwater mussel from Thailand (Bivalvia: Unionidae)
No full textFig. 4. Bayesian inference tree based on 1,967 bp concatenated alignment dataset of COI + 16S + 28S genes. Numbers on nodes indicate bootstrap values from maximum likelihood (ML) and bipartition posterior probabilities from Bayesian inference analysis (BI), and are shown as BI/ML. Black circles on nodes indicate high support by BI (≥ 0.95) and ML (≥ 70); white circles indicate high support by BI. Shells are not to scale.Published as part of Jeratthitikul, Ekgachai, Paphatmethin, Siwanon, Zieritz, Alexandra, Lopes-Lima, Manuel & Ngor, Peng Bun, 2021, Hyriopsis panhai, a new species of freshwater mussel from Thailand (Bivalvia: Unionidae), pp. 124-136 in Raffles Bulletin of Zoology 69 on page 134, DOI: 10.26107/RBZ-2021-0011, http://zenodo.org/record/535198
Development and evaluation of hotshot protocols for cost-and time-effective extraction of PCR-ready DNA from single freshwater mussel larvae (Bivalvia: Unionida)
No full textFreshwater mussels (Unionida) are unique in that their larvae (glochidium, haustorium or lasidium) parasitize vertebrate hosts, with a given mussel species metamorphosing only on a limited array of host species (Wächtler, Mansur & Richter, 2001). Collecting data on host fish identities is important for both conservation and commercial applications, but requires identification of single larvae to species level. This is most efficiently achieved by molecular species identification (White, McPheron & Stauffer, 1996; Kneeland & Rhymer, 2007, 2008; Boyer et al., 2011; Zieritz et al., 2012; Vannarattanarat et al., 2014), because morphological identification of larval mussels is time-consuming and sometimes unreliable (Wiles, 1975; O’brien, Williams & Hoggarth, 2003)
Figure 3 in Mitogenomic phylogeny and fossil-calibrated mutation rates for all F- and M-type mtDNA genes of the largest freshwater mussel family, the Unionidae (Bivalvia)
No full textFigure 3. Phylogenetic tree of the Unionidae+Margaritiferidae estimated from 14 concatenated individual mtDNA gene sequences (12 protein-coding and 2 rRNA genes). Values for branch support above each node represent Bayesian posterior probabilities percentage/maximum likelihood bootstrap support. *Supported values ≥ 95 are represented by an asterisk.Published as part of Zieritz, Alexandra, Froufe, Elsa, Bolotov, Ivan, Gonçalves, Duarte V., Aldridge, David C., Bogan, Arthur E., Gan, Han Ming, Gomes-Dos-Santos, André, Sousa, Ronaldo, Teixeira, Amilcar, Varandas, Simone, Zanatta, David & Lopes-Lima, Manuel, 2020, Mitogenomic phylogeny and fossil-calibrated mutation rates for all F- and M-type mtDNA genes of the largest freshwater mussel family, the Unionidae (Bivalvia), pp. 1088-1107 in Zoological Journal of the Linnean Society 193 on page 1098, DOI: 10.5281/zenodo.563569
High endemic freshwater mussel (Bivalvia: Unionida) diversity in western Borneo, with description of three new species
No full textThe freshwater mussels (Bivalvia: Unionida) of the biodiversity hotspot Sundaland are experiencing severe anthropogenic threats, whilst their diversity and distribution remain poorly understood. Here, we present the first modern-day data on Unionida diversity and distribution across western Borneo. Mussels were surveyed and collected in the upper Kapuas and Pawan river basins in West Kalimantan, Indonesia, and the Sambas Besar, Sarawak and Batang Sadong river basins in Sarawak, Malaysia. DNA sequencing (COI + 16S + ND1 + 18S + 28S) and morphological analyses were conducted to delineate and identify species, and reconstruct phylogenetic relationships and population genetics. Specimens belonged to six native genera and nine species, of which seven are endemic to Borneo and three are new to science, i.e. Ctenodesma mawonae Zieritz et al., sp. nov., Sarawak basin, and Ctenodesma bersinara Zieritz et al., sp. nov., and Rectidens lauris Zieritz et al., sp. nov., both Pawan basin. The monotypic genera Caudiculatus and Discomya were phylogenetically highly divergent from other known Gonideinae taxa, potentially indicating a separate tribe (for Caudiculatus) and subfamily (for Discomya). In addition, we report new records of the non-native Sinanodonta pacifica Heude, 1878 in the Batang Sadong and Kapuas river basins
High endemic freshwater mussel (Bivalvia: Unionida) diversity in western Borneo, with description of three new species
No full textTe freshwater mussels (Bivalvia: Unionida) of the biodiversity hotspot Sundaland are experiencing severe anthropogenic threats, whilst their diversity and distribution remain poorly understood. Here, we present the frst modern-day data on Unionida diversity and distribution across western Borneo. Mussels were surveyed and collected in the upper Kapuas and Pawan river basins in West Kalimantan, Indonesia, and the Sambas Besar, Sarawak and Batang Sadong river basins in Sarawak, Malaysia. DNA sequencing (COI + 16S + ND1 + 18S + 28S) and morphological analyses were conducted to delineate and identify species, and reconstruct phylogenetic relationships and population genetics. Specimens belonged to six native genera and nine species, of which seven are endemic to Borneo and three are new to science, i.e. Ctenodesma mawonae Zieritz et al., sp. nov., Sarawak basin, and Ctenodesma bersinara Zieritz et al., sp. nov., and Rectidens lauris Zieritz et al., sp. nov., both Pawan basin. Te monotypic genera Caudiculatus and Discomya were phylogenetically highly divergent from other known Gonideinae taxa, potentially indicating a separate tribe (for Caudiculatus) and subfamily (for Discomya). In addition, we report new records of the non-native Sinanodonta pacifca Heude, 1878 in the Batang Sadong and Kapuas river basins
Supplementary material 1 from: Zieritz A, Armas B, Aldridge D (2014) Registry of non-native species in the Two Seas region countries (Great Britain, France, Belgium and the Netherlands). NeoBiota 23: 65-80. https://doi.org/10.3897/neobiota.23.5665
No full textRegistry of non-native species in the Two Seas region countries (Great Britain, France, Belgium and the Netherlands): Explanation note: The MS Excel file contains two worksheets
Phylogeny of European Anodontini (Bivalvia: Unionidae) with a redescription of Anodonta exulcerata
No full textFreshwater bivalves are highly threatened and globally declining due to multiple anthropogenic impacts, making them important conservation targets. Because conservation policies and actions generally occur at the species level, accurate species identification and delimitation is critical. A recent phylogenetic study of Italian mussel populations revalidated an Anodonta species bringing the number of known European Anodontini from three to four species. The current study contributes to the clarification of the taxonomy and systematics of European Anodontini, using a combination of molecular, morphological and anatomical data, and constructs phylogenies based on complete mitogenomes. A redescription of A. exulcerata and a comparative analysis of morphological and anatomical characters with respect to the other two species of Anodonta present in the area are provided. No reliable diagnostic character has emerged from comparative analysis of the morphometric characters of 109 specimens from 16 sites across the Italian peninsula. In fact, the discriminant analysis resulted in a greater probability of correct assignment to the site of origin than to the species. This confirms the difficulties of an uncritical application of visual characters for the delimitation of species, especially for Anodontinae
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