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Classification


Geographic Distribution

Antarctic Convergence illustration Antarctic convergence

Desmonema glaciale Larson, 1986  Species

Original Description
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Original Description
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"Umbrella to 1.2 m in diameter. Exumbrella: smooth, with mesoglea at center. Umbrellar margin: divided into 24 lappets more or less distinct; velar lappets: 8, broadly rounded, alternating with paired rhopaliar lappets: 16, lingulate. Rhopalia: 8, in deep niches between rhopaliar lappets. Tentacles: subumbrellar, in 8 adjacent groups, less than 10 per group, flattened, noticeably thick (3-5 mm or more in diameter), very long (greater than 5 mm), adjacent to periphery coronal muscle, arranged in a single linear row across proximal portion of velar lappets only. Coronal muscle: circular, folded, well-developed, divided by radial septa into 16 trapezoidal muscle fields; velar muscle fields alternate with somewhat narrower rhopaliar fields. Oral arms: 4, broad, curtainlike, pleated, about length of umbrella diameter or longer. Gonads: 4, large, saclike, everted, about 1/3 length of oral arms. Gastric pouches: 16, velar pouches slightly broader than rhopaliar pouches, terminating as blind-ending (rarely anastomosing) canals. Velar canals: dendritic, about equal in number at origin to tentacles, branching 3-4 times (mostly unilaterally) with branches becoming progressively shorter. Rhopaliar canals: single and broad at origin but narrowing toward umbrellar margin and branching bilaterally into short secondary and tertiary branches. Color: in preserved specimens, uniformly pink; in life, pink-violet."

(Larson, 1986)

Remarks

"This giant medusa, well known in Antarctic waters as Desmonema gaudichaudi sensu Maas [1908], is herein described as the new species Desmonema glaciale. It is unmistakably distinct from the other Desmonema species because of its large size (1.2 m or more in bell diameter) and cordlike tentacles which are few in number (less than 10 per group), and because of its restricted Antarctic distribution. Previously, the stout tentacle fragments of D. glaciale n. sp. were described by Rennie [1905, 1907] as tentacles of siphonophores.

White and Bone [1972] have reported this medusa's association with hyperiid amphiods, and have also noted its diet and other aspects of its biology. In addition, they suggested that this medusa is present in the South Orkney Islands throughout the year, although they mostly observed it in the early spring."

(Larson, 1986)

Specimens

Type Status Catalog No. Date Collected Location Coordinates Depth (m) Vessel
Holotype 53749 11/1966 Ross Sea      
Paratype 53690 2/19/1966 Antarctic Ocean 62.1° S, 57.8° W    
Paratype 53691 2/1/1963 Antarctic Ocean 64.82° S, 62.9° W   Staten Island R/V
Paratype 58892   Ross Sea     Staten Island R/V

View additional taxa  View all species collected at same locations as Desmonema glaciale