Pliocene deposits cropping out in the Agua Amarga subbasin (Almería, SE Spain) include a composite shell bed made up of variously preserved and densely packed mollusks. The characteristics of the shell bed indicate deposition in shallow marine settings under a changeable sedimentation rate. The composite shell bed was formed through the amalgamation of several depositional events, mostly connected with storm events. During relatively slow sedimentation the bivalve Panopea colonized the substratum. The colonization took place over different stages of the shell bed formation, as reflected by differently preserved Panopea scattered throughout the shell bed. The upper part of the shell bed contains several tens of Panopea preserved within their burrows: Scalichnus cf. phiale Hanken et al., 2001. All bivalves in S. cf. phiale are articulated and preserved in life position. They are confined to a single horizon and most probably represent a single fossil population composed of adult individuals of Panopea resulting from anastrophic burial by storm deposits. As a consequence, the bivalves in their burrows succumbed at the same time; that is, the study case represents an “ecological snapshot” or ecological census.

The present research aimed at evaluating the influence of the water quality in the life cycle and attraction of Aedes aegypti (L.) females to oviposit using different sources of water (raw sewage, effluent of UASB reactor, effluent of polishing lagoon, effluent of anaerobic filter, rain water and de-chlorinated water). The immature development time and survivorship were evaluated on a daily basis in two distinct feeding systems (with and without food). The quality of the water was shown to affect the egg and larval stages, but not the pupal or the adult. In the absence of food, no development was observed in rain water and de-chlorinated water. Immature development was faster in water sources from raw sewage, although with the lowest survivorship (37.3%). Free-choice tests indicated that females preferred to lay most of their eggs on water collected from the effluent of a UASB reactor, achieving the highest oviposition activity index (OAI) of 0.57. In non-choice tests, females laid larger batches of eggs in water collected from anaerobic filters (204.8 eggs), with the lowest number of eggs being laid on de-chlorinated water (37.3 eggs). It can be concluded that A. aegypti does not demonstrate any particular preference to lay eggs on clean water. This has serious implications for developing strategies to manage populations of this important vector in urban areas as it was shown to lay eggs and successfully develop on several different sources of water.