1. | 3 | 2. | 4 |
3. | 5 | 4. | 6 |
I: | They are marine but migrate for spawning to fresh water. |
II: | After spawning, within a few days, they die. |
III: | Their larvae, after metamorphosis, return to the ocean. |
1. | Petromyzon, Myxine |
2. | Ascidia, Salpa |
3. | Pristis, Doliolum |
4. | Branchiostoma, Balanoglossus |
Identify the incorrect statement regarding cyclostomes:
1. | Lampreys have direct development, but Hagfishes go through a larval stage followed by metamorphosis into a juvenile form. |
2. | Unlike jawed vertebrates, which have three semicircular canals in each inner ear, lampreys have only two and hagfishes just one. |
3. | The hagfish blood is isotonic with seawater, while lampreys appear to use the same gill-based mechanisms of osmoregulation as marine teleosts. |
4. | Both hagfishes and lampreys have a single gonad. |