Spawning random enemies in spawn points

I have side scrolling game (almost) and I have a little problem with enemy spawnig. I already have spawn points located on map and whenever my BGLooper collides with spawn point it’s gonna move forward, next to last spawn point. I can’t figure how to spawn 1 of my 8 enemies in each spawnpoint randomly. Any ideas?

using UnityEngine;
using System.Collections;

public class BGLooper : MonoBehaviour {

	int numBGPanels = 6;

	float minEnemy = 1;
	float maxEnemy = 8;
	

	void OnTriggerEnter2D(Collider2D collider) {
		Debug.Log ("Triggered: " + collider.name);

		float widthOfBGObject = ((BoxCollider2D)collider).size.x;
		
		Vector3 pos = collider.transform.position;
		
		pos.x += widthOfBGObject * numBGPanels;

		collider.transform.position = pos;

		if (collider.tag == "Enemy") {


				}
	}
}

int enemyType = Mathf.RoundRandom.Range(0,numberOfDifferentEnemys));
Instantiate(EnemyPrefabAray[enemyType],spawnpointPosition ,Quaternion.identity) //not sure about the rotation