The original Peano axioms were based on a single unary operator $\operatorname{succ}$ and one second-order induction axiom: $\lbrace \operatorname{succ} \rbrace + \operatorname{IND}_2$
Peano arithmetic is the first-order theory with additional explicit axioms for additional binary operators $+$ and $\times$ and the second-order induction axiom replaced by a first-order axiom schema: $\lbrace \operatorname{succ}, + ,\times\rbrace + \operatorname{IND}_1$
Presburger arithmetic is the first-order theory with additional axioms for one additional binary operator $+$ and a first-order induction axiom schema: : $\lbrace \operatorname{succ}, + \rbrace + \operatorname{IND}_1$
Skolem arithmetic is $\lbrace \operatorname{\times} \rbrace + \operatorname{IND}_1$ [added]
Robinson arithmetic is Peano arithmetic without induction: : $\lbrace \operatorname{succ}, + ,\times\rbrace - \operatorname{IND}_1$
What about other conceivable arithmetics, e.g.
- $\lbrace \operatorname{succ} \rbrace \pm \operatorname{IND}_1$
- $\lbrace \operatorname{succ, \leq} \rbrace \pm \operatorname{IND}_1$
- $\lbrace \operatorname{succ} , + \rbrace - \operatorname{IND}_1$
- $\lbrace \operatorname{succ}, +, \times, \operatorname{exp}\rbrace \pm \operatorname{IND}_1$
Which of them was given a name, which of them were investigated?