Table 2.
Genome Size, Heterozygosity, and Repeat Elements
| Subclass | Order | Family | Species | Estimated Genome Size (Gb) | Heterozygosity (%) | % of Repeated Elements |
|---|---|---|---|---|---|---|
| Palaeoheterodonta | Unionida | Unionidae | Venustaconcha ellipsiformis | 1.80 | 0.63 | 37.81 |
| Heterodonta | Veneroida | Veneridae | Ruditapes philippinarum | 1.37 | high* | 26.38 |
| Pteriomorphia | Mytiloida | Mytilidae | Bathymodiolus platifrons | 1.64 | 1.24 | 47.90 |
| Modiolus philippinarum | 2.38 | 2.02 | 62.00 | |||
| Mytilus galloprovincialis | 1.60 | high* | 36.13 | |||
| Limnoperna fortune | 1.67 | 2.3 | 33.00 | |||
| Ostreoida | Ostreidae | Crassostrea gigas | 0.55 | 1.95 | 36.00 | |
| Pectinidae | Chlamys farreri | 0.95 | 0.8 | 32.10 | ||
| Patinopecten yessoensis | 1.43 | 0.45 | 38.87 | |||
| Pterioida | Pteriidae | Pinctada fucata | 1.15 | high* | 37.00 | |
| Pteriomorphia mean (SD) | 1.39 (0.58) | 1.29 (0.70) | 41.43 (10.29) | |||
| Mytiloida mean (SD) | 1.87 (0.44) | 1.52 (0.68) | 48.68 (12.95) | |||
| Ostreoida mean (SD) | 0.98 (0.44) | 1.07 (0.78) | 35.66 (3.40) | |||
| Pectinidae mean (SD) | 1.19 (0.34) | 0.63 (0.25) | 35.49 (4.79) | |||
| All subclasses mean (SD) | 1.41 (0.51) | 1.20 (0.69) | 39.35 (10.23) |
Note.—Estimates of genome size, heterozygosity, and percentage of repeated elements in the currently available bivalve nuclear genomes. Data for each single species were retrieved from the literature: P. yessoensis (highly inbreed individual, Wang et al. 2017), V. ellipsiformis (wild, recurrent population bottlenecks, this study), C. farreri (selective breeding in aquaculture, Li et al. 2017), B. platifrons (recurrent population bottlenecks in the wild, Sun et al. 2017), C. gigas (highly inbreed individual, Zhang et al. 2012), M. philippinarum (large wild population, Sun et al. 2017), L. fortunei (invasive worlwide, Uliano-Silva et al. 2018), R. philippinarum (selective breeding in aquaculture, Mun et al. 2017), P. fucata (selective breeding in aquaculture, Takeuchi et al. 2012), M. galloprovincialis (large wild population, Murgarella et al. 2016). The genome size for V. ellipsiformis was based on k-mer analysis (see Materials and Methods). Mean and standard deviation (SD) values are also shown for the taxa comprising more than one species and for all subclasses, that is, the class Bivalvia. Note that all species are marine, except for V. ellipsiformis and L. fortunei (freshwater).
no rate calculated, but “high” heterozygosity documented.