Cirrothauma magna Description Continued

1. Arms
   1. Arms 3.5 - 5 times ML.
   2. All arms with 29 prominent proximal suckers, diameter small.
   3. Suckers 5-7 cyclindrical with thick, stout stalk, separated by 1 cm,
   4. Following suckers, separated by 2-3 cm, with long stalks, and and with "small circular opening surrounded by very narrow rim in the upper part, with narrow infundibulum; acetabulum [a] broad chamber surrounded by highly deformable fleshy membrane in such a way that the acetabulum is able to inflate and deflate, forming spherical, flattened or half-closed eyelid."
   5. Proximal suckers commonly appear folded.
   6. Distal suckers (suckers number 30 +) abruptly different appearance: muscular with spherical base embedded in arm, bowl or barrel-shaped distal portion; suckers sessile.
   7. Distal suckers gradually increase in size to SDI 4.6 then decrease to arm tip.
   8. First minute cirri between suckers 4 and 5.
   9. Maximum cirri length (CiLI 71-95) 10-14 times sucker diameter.
   

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   Figure. Oral view of an arm of C. magna, male, mature, 220 mm ML, showing arrangement of suckers and cirri. Distal half on top, proximal half on bottom. Drawing from Guerra, et al., 1998.

2. Mantle cavity
   1. Gills sepioid with 5-6 primary lamellae in outer demibranch.
   

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   Figure. Left - Ventral view of the mantle cavity of C. magna, mature male 220 mm ML. Right - "Top" view of the gills of C. magna, mature male 220 mm ML. Drawing and photograph from Guerra, et al., 1998.

3. Digestive system
   1. Forms a simple loop.
   2. Digestive gland heart-shaped and olive-green color.
   3. Radula absent.
   4. Caecum larger than stomach, not forming spiral.
   

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   Figure. Side view of the digestive tract of C. magna, mature male 220 mm ML. Drawing from Guerra, et al., 1998.

4. Male reproductive system
   1. Accessory glands large; three glands covered by dark purple sac.
   2. Penis small, cyclindrical.
   

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   Figure. Male reproductive system of C. magna, mature male 220 mm ML. Drawing from Guerra, et al., 1998.

5. Female reproductive system
   1. Distal portion of oviducal gland much larger than proximal portion.
   2. Distal and proximal oviducts short.
   3. Largest oocytes in ovary 10x8 mm.
   

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   Figure. Female reproductive system of C. magna, submature female, 140 mm ML. Drawing from Guerra, et al., 1998.

6. Shell
   1. Butterfly-shaped.
   

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   Figure. Shell of C. magna, submature female, 140 mm ML. Left - Dorsal view. Right - ventral view. Drawings from Guerra, et al., 1998.

7. Beaks
   1. Beaks large, thick and robust.
   

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   Figure. Beaks of C. magna, mature male 220 mm ML. Left - Upper beak, lateral view.  Middle - Lower beak, lateral view. Right - Lower beak, ventral view. Drawings from Guerra, et al., 1998.

8. Pigmentation
   1. Arms translucent.
   2. Body and arms vary from pale white to purple.
   3. Oral surfaces of arms and web darkest, purple or purple-brown.
   4. Suckers lack pigmentation.
   5. Cirri chesnut-brown.
   6. Esophagus dark purple-black; stomach brown; caecum gray; intestine dark purple.
      
      
9. Measurements and counts.

Sex       measurements in mm	Female Holotype	Male	Female
Mantle length	175	220	140
Total length	1155	1075	870
Head width	100	105	89
Mantle width	125	170	80
Fin length	200	156	130
Fin width	76	74	65
Fin span	513	483	321
Eye diameter	-	85	60
Lens diameter	29	28	25
Mantle opening	22	22	20
Arm I, length	875/875	748/790	690/-
Arm II, length	870/875	710/700	-/-
Arm III, length	870/890	685/690	-/-
Arm IV, length	838/915	745/565	-/-
Cirrus length, max.	80	72	85
Sucker diameter, max.	8	9	6
Gill length	37	25	24
Gill width	30	27	20
Gill lamellae/demibranch	5/5	6/6	5/6
Penis length		6
Shell width	85	66.5	61.5
Shell saddle length	22	20	18.7

Measurements are taken from Guerra, et al., 1998.

Comments

The above description is taken from Guerra, et al., 1998.

References

Guerra, R., R. Villanueva, K. N. Nesis and J. Bedoya. 1998. Redescription of the deep-sea cirrate octopod Cirroteuthis magna Hoyle, 1885, and considerations on the genus Cirroteuthis (Mollusca: Cephalopoda). Bull. Mar. Sci., 63: 51-81.