Zoology · Ch 4 — Organ and Organ Systems in Animals
Morphology
Morphology
Lampito mauritii has a long, narrow, cylindrical body that is bilaterally symmetrical, typically 80 to 210 mm long and 3.5 to 5 mm wide, light brown in colour with a purplish tinge towards the front caused by a respiratory pigment called porphyrin. A large number of external grooves divide the body into roughly 165 to 190 ring-like segments, or metameres. A dark mid-dorsal line along the back marks the position of the dorsal blood vessel just beneath the skin. The first segment carries the mouth (the peristomium), overhung by a small flap called the prostomium, while the last segment carries the anus (the pygidium). In sexually mature worms, segments 14 to 17 are swollen and glandular, forming the clitellum, which divides the body into a pre-clitellar, clitellar and post-clitellar region and later secretes the cocoon. Every segment except the first, last and clitellar ones bears a ring of small, S-shaped chitinous setae used in locomotion. Other extern …
What this figure shows. Whole-worm views (entire animal, dorsal view, ventral view) plus a close-up of the S-shaped body setae, labelling the anus, clitellum, dorsal pores, mouth, prostomium, the opening of the oviduct, the openings of the spermathecae, and the opening of the vas deferens, showing where each aperture sits along the se …
| S.No | Characters | Lampito mauritii | Metaphire posthuma |
|---|---|---|---|
| 1 | Shape and size | Cylindrical, 80 mm - 210 mm in length, 3.5 mm - 5.0 mm in width | Cylindrical, 115 - 130 mm in length, 5 mm in width |
| 2 | Colouration | Light Brown | Dark Brown |
| 3 | Segmentation | 165 - 190 Segments | About 140 Segments |
| 4 | Clitellum | 14th - 17th Segments (4) | 14th - 16th Segments (3) |
| 5 | Spermathecal opening | Three pairs 6/7, 7/8 and 8/9 | Four pairs 5/6, 6/7, 7/8 and 8/9 |
| 6 | Pharynx | 3rd - 4th segment | Runs up to 4th Segment |
| 7 | Oesophagus | 5th segment | 8th segment |
| 8 | Gizzard | 6th segment | 8th - 9th segment |
| 9 | Intestine | 7th segment to anus | 15th segment to anus |
| 10 | Intestinal caeca | Absent | Present in 26th segment |
| 11 | Lateral hearts | 8 pairs from 6th to 13th segments | 3 pairs from 7th to 9th segments |
| 12 | Pharyngeal nephridia | 5th - 9th segment | 4th - 6th segment |
| 13 | Micronephridia | 14th to last segment | 7th to last segment |