Need my fish character to move up and down, not just left and right.

using UnityEngine; using System.Collections; using UnityEngine.UI; public class CONTROLLER : MonoBehaviour {

 public Rigidbody2D thisRigidbody;
 public float speed = 5;
 public float jumpSpeed = 5;
 private bool grounded = true;
 public int Hero_Score = 0;
 public Text scoreText;

 // Use this for initialization
 void Start() { }

 // Update is called once per frame
 void Update() { }

 void FixedUpdate()
 {
     var move = new Vector3(Input.GetAxis("Horizontal"), 0, 0);
     transform.position += move * speed * Time.deltaTime;


     if (Input.GetKey(KeyCode.UpArrow) && grounded == true)
     {
         grounded = false;
         thisRigidbody.velocity = new Vector3(0, jumpSpeed, 0);
     }

 }
          
 

 void OnCollisionEnter2D(Collision2D col)
 {
     if (col.gameObject.tag == "BLOCK") {
         grounded = true;
     }

     if (col.gameObject.tag == "ITEM") {
         //Add Score
         Destroy (col.gameObject);
         Hero_Score += 1;
         scoreText.text = "Keys:" + Hero_Score.ToString ();

     }
     if (col.gameObject.tag == "end") {
         Application.LoadLevel ("WINNER SCREEN");


     }
     if (col.gameObject.tag == "enemy") {
         Application.LoadLevel ("lost_screen");
     }

 }

}