I am looking at some English translations of Latin texts (direction which I think is important to highlight), and I'm not sure there is an equivalent word in Latin.
Example 1:
These organs are placed against it but under it, on the right and left sides respectively.
Haec viscera proxuma sed infra tamen posita dextra sinistraque sunt.
Example 2:
T. Otacilius and M. Valerius were ordered to cruise off the coasts of Sicily and Greece respectively with the fleets and soldiers they had previously commanded.
T. Otacilio et M. Valerio Siciliae Graeciaeque orae cum legionibus classibusque quibus praeerant decretae;
Example 3:
So we often have Leuconotus and Altanus blowing respectively to the right and left of Auster;
Itaque dextra et sinistra austrum leuconotus et altanus flare solet,
Given these examples, it seems to me that "respectively" is not needed in Latin because some obviously assumed correspondence. For example, in T. Otacilio et M. Valerio Siciliae Graeciaeque a Latin reader would unambiguously know that Siciliae refers to Otacilio. This is perhaps also the case (but less strongly) in English, where the addition of "respectively" is just to add emphasis, without being determinant in the understanding of the correspondence.