Organisms don't have adapter sequences. Adapter sequences are ligated onto the library fragments prior to sequencing as part of the library preparation process. You'll need to ask someone at the sequencing facility for the adapter sequences, or ask which kit they used for the library prep and obtain the sequences from the vendor.

If for some reason no one can provide that information to you, a quick way to possibly find adapter sequences if they exist is to use FastQC. Look in the "Overrepresented Sequences" section of the report after you run an untrimmed FASTQ file through it.