Ihlea magalhanica
Apstein (1894)
Download a fact sheet for Ihlea magalhanica (PDF 370KB)
Taxonomy
| Phylum | Chordata |
| Class | Thaliacea |
| Order | Salpida |
| Family | Salpidae |
| Genus | Ihlea |
| Species | magalhanica |
Size
- Aggregate form up to 22 mm
- Solitary form up to 39 mm (without process)
Distinguishing characteristics
Aggregate form
Body
- Zooids strongly symmetrical
- Almost oval shape
- Small lateral process anteriorly, longer process posteriorly
- Openings are terminal
- Test soft
- Preserved specimens appear flat
Muscles
- 5 asymmetrical body muscles
- M1-M3 join dorsally, M2-M3 join medio ventrally by anastiamosis
- M3-M4 approach and may touch on either side
- M4-M5 approach or touch dorsally
- M5 broken ventrally
- Number of muscular fibres of MII: 25-40
- Dorsal tubercle
- Moderate length
- Curves inwards at either end
Gut
- Moderate circular or oval nucleus
Solitary form
Body
- Cylindrical
- Soft test and terminal openings
Muscles
- 7 body muscles variously curved
- Very broad muscles, except M7 which divides ventrally
- M1-M4 approach or touch (do not fuse) dorsally and ventrally
- M4-M5 touch laterally
- M5-M6 approach or touch dorsally
- Number of muscular fibers of MII: 77-148
- Dorsal tubercle
- Slightly coiled in the dorso-ventral plane
- Comparatively large
Gut
- Compact nucleus, blind sac directed posteriorly
- Stolon exiting ventrally, immediately ahead of nucleus
Distribution
- Common in SE Australian waters from October to February
Ecology
- Low tolerance for warm water, indicator for cold water
References
- Thompson, H. (1948). Pelagic tunicates of Australia, CSIRO, Melbourne, Australia.
- Van Couwelaar, M. (2003). Zooplankton and micronekton of the North Sea. Expert Center for Taxonomic Identification, Amsterdam.