Table 2. Characteristics of ranavirus associated mortality events, grouped by distance from the index site (no. 0).
ND = Not determined. NA = Not applicable. All = No, or virtually no, live specimens remain in the water body in the immediate aftermath of the initial mortality event.
| Km to index site | Phylo- group no. | Site no. | Site type* | Month and year identified | (Estimate of) numbers dead | Life stages†-species‡ affected, per phenological frequency of the life stage at time of the event | Situation Pelophylax spp. in 2014 | ||
|---|---|---|---|---|---|---|---|---|---|
| High | Moderate | Low | |||||||
| ≤20 | I | 7 | G | May 2011 | 100–1000 (all) | L-Bb | A-P, A-Bb | Unknown | |
| I | 9 | G | Jul. 2011 | 100–1000 (all) | L-Lv | L- P | A-P | Pond renovated | |
| I | 11 | G | Aug. 2011 | 10–100 (all) | J-Lv | L- P, L- Lv, J- P | A-P | Reduced § | |
| I | 13 | G | Sep. 2011 | 10–100 | A-P | Reduced § | |||
| I | 25 | La | Jun. 2012 | ≥1000 | L-Pf | L- Lv | Unknown | ||
| I | 35 | G | Aug. 2013 | 100–1000 | L- P | A-P | Reduced § | ||
| I | 36 | La | Aug. 2013 | ≥1000 (all) | J-P, J-Lv | L- P | A-P | Reduced § | |
| I | 37 | N | Aug. 2013 | 100–1000 (all) | J-P, J-Lv | L- P | A-P, A-Lv | Reduced § | |
| ND | 38 | G | Sep. 2013 | 10–100 (all) | A-P, A-Lv | Reduced § | |||
| I | 45 | G | May 2014 | 10–100 | A-P | NA | |||
| I | 48 | N | Jul. 2014 | 10–100 | L-P, L-Lv | A-P | A-Lv | NA | |
| I | 51 | N | Sep. 2014 | 10–100 | A-P | NA | |||
| 55–60 | I | 30 | S | Apr. 2013 | 10–100 | A-Rt | Unknown | ||
| ND | 43¶ | N | May 2014 | 1–10 | A-Lv | NA | |||
| ND | 52¶ | Po | Sep. 2014 | 1–10 | A-Bb | NA | |||
| >150 | II | 33 | N | Jul. 2013 | 10–100 | L-P, L-Lv | A-P | No effect | |
| II | 47 | La | Jul. 2014 | 10–100 | L-Pf#, A-P | NA | |||
| ND | 49¶ | La | Aug. 2014 | 1–10 | L-P | NA | |||
* G = garden pond; La = landscaped pool (natural pool remodeled by humans); N = natural pool; Po = pond; S = stream.
† L = larvae; J = juveniles; A = (sub-)adults.
‡ Bb = Bufo bufo; Lv = Lissotriton vulgaris; Pf = Pelobates fuscus; P = Pelophylax spp. (three species P. kl. esculentus, P. lessonae and P. ridibundus, grouped here because visually undistinguishable at larval stage; adult specimens of all three species shown to be infected); Rt = Rana temporaria.
§ The number of adult Pelophylax spp. seen by garden pond owners was ≤ 10% of the pre-epidemic numbers after a year (no. 11, 13, 38) and ≤ 20% of the pre-epidemic numbers after 3 years (no. 11, 13). Egg masses and larvae were often absent. A field visit to sites no. 36 and 37 a year later showed ≤ 10% of the pre-epidemic numbers. Only descriptive data was provided for site no. 35.
¶ At site no. 43, the PCR-test positive specimen (Lissotriton vulgaris) was IHC negative, and at sites no. 49 (Pelophylax kl. esculentus) and no. 52 (Bufo bufo), the specimens had no histological lesions consistent with ranavirus. At all other sites, all three methods gave results consistent with ranavirus infection.
# Site no. 47 is a landscaped pool, in which nearly full-grown spadefoot toad larvae were reintroduced in 2014. Therefore, phenological frequency does not really apply to these spadefoot toad larvae. The larvae had hatched and had been raised in captivity from egg masses taken earlier that year from site no. 25, a known ranavirus-positive site.