[R-sig-ME] semicontinuous variables: what likelihoods are available?

[Aurelie Cosandey Godin]

Dear list,

I need to run spatio-temporal models for a semicontinuous response variable (weight in kg). 
I am not familiar with the available semicontinuous likelihood functions available in R and was wondering if some of you may be able to point me in the right direction for information.

Many thanks in advance!
Aurelie