Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Predation by Atractosteus tropicus on Bufo marinus and its possible
  affect on population in a lowland tropical wet rainforest   Fish predation can affect amphibian populations. Most examples report
invasive fish species and their negative effect on specific amphibians. Here we
provide an occurrence of natural fish predation by the tropical gar
Atractosteus tropicus on the cane toad Bufo marinus. We observed physical
damage caused by A. tropicus attacking B. marinus. When adult B. marinus were
removed from the population subadult toads refilled the adults niche,
resupplementing the population. Local observations of predation by fish on
amphibians are important to differentiate natural population fluctuations from
amphibian population declines.

37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess