Registration Dossier

Administrative data

Endpoint:
additional ecotoxicological information
Type of information:
experimental study
Adequacy of study:
disregarded due to major methodological deficiencies
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Publication of low reliability. E.g.: 1) although the method of ovocyte production is reported to be prone to developmental anomalies no precautionary measures by randomisation of allocation to groups was performed; 2) the cause of starving of the larvae is stated to be the malformations, without proof and not vice versa, although it is known from mammals that starving can produce malformations; 3) dosing caused a high mortality ( without giving a time scale) so that malformations are not unlikely; etc.

Data source

Reference
Reference Type:
publication
Title:
Teratogenic Effects and Cannabalism Caused by Melamine on Bufo arenarum Larvae
Author:
Rengel D, Pisano A
Year:
1994
Bibliographic source:
Biocell, 18:13-19

Materials and methods

Principles of method if other than guideline:
Chronic exposure of Bufo arenarum larvae
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Melamine was obtained from Sigma

Results and discussion

Any other information on results incl. tables

The development of treated embryos was delayed when compared with control groups.

Treated larvae did not eat well, as a consequence treated larvae volume was more reduced than that of control groups even though their larval stage was similar. Treated larvae developed slowly or just stood at the first larval stages.

Larvae treated with 1 or 2 g ‰ Melamine did not eat vegetable food, instead they ate either cachectic or dead larvae (larval cannibalism process is an unusual behaviour in this species).

Treated larvae developed a losange-like shape instead of typical contour of the control. Also their mouth was different.

The digestive system of the treated larvae did not present the typical spiralization seen in control larvae. Liver and pancreas had lesser volume than control. Gallbladder was very large. Urogenital system showed significant alterations caused by Melamine.

Applicant's summary and conclusion

Conclusions:
Chronic Melamine exposure has teratogenic effects and causes cannibalism in Bufo arenarum larvae.
Executive summary:

The chronic effects of melamine on Bufo arenarum development was analyzed using 0.25, 0.5, 1 and 2 g ‰ doses. This pollutant showed a greater teratogenic action at higher concentrations and caused anomalous features on the mouth, an atypcial differentiation of the digestive system switching from herbivorous to carnivorous, forcing larvae to cannibalism. Inner gills always reduced were formed with difficulties. Gonad evidenced a lack of germinal cells and renal tubules showed anatomical modifications. According to doses, Melamine has more or less drastic effects on the mortality of larvae.