Argonauta, Linnaeus, 1758

Mohanty, Swarup Ranjan, Tudu, Prasad Chandra & Mohapatra, Anil, 2021, Short Communication Argonauta hians Lightfoot, 1786 (Cephalopoda: Argonautidae): A new record to the northern east coast of India, Records of the Zoological Survey of India 121 (1), pp. 201-204 : 202

Argonauta hians Lightfoot, 1786 ( Figure 1 )

1881. Argonauta boettgeri Maltzan, Journal de Conchyliologie, 29: 162–163.

2000. Argonauta boettgeri: Subba Rao and Dey, Rec. zool. Surv. India. Occ. Pap., 187: 198.

2010. Argonauta hians: Ramakrishna and Dey, Rec. zool. Surv. India. Occ. Pap., 320: 33.

Common name: Brown Paper Nautilus, Winged Argonaut, Muddy Argonaut preservation but in fresh, it was light brown with black pigmentation of surface of the shell on lateral view. Inside of the shell is completely white on abapertural view ( Figure 1 ).

Distribution: In India: Andaman and Nicobar Islands, Gulf of Mannar (Tamil Nadu), and Maharashtra and Kerala ( Ravinesh et al., 2017) ( Figure 2 ), Elsewhere: In Indo-west Pacific from South Africa in the west, to Papua New Guinea in the east, Japan in the north and Australia in south, including the north Indian Ocean, Arabian Sea, Andaman Sea, Moluccas, Philippines and China Sea Finn, 2013.

Material examined: EBRC /ZSI/M 12030, 1 ex., shell with animal, length 64 mm; maximum shell breadth 39 mm, Paradip fish landing centre, Paradip , Odisha, 11 th March 2020, coll. Swarup Ranjan Mohanty.

Characters: Female: Body muscular, skin smooth; slender and having unequal eight arms; 4 arms on each side. Each arm with two rows of sucker and 4 th arm on both left and right side shorter than the 2 nd and 3 rd arms. First arm with 60 suckers and second, third and fourth arms are having 58, 40 and 52 suckers, respectively. The present specimen was considered as a juvenile as having a smaller number of suckers in the arms and smaller mantle and shell size (details in discussion). Head narrow embedded within mantle with two large and protrude eyes on both sides. Shell large, laterally flattened, with smooth lateral ribs. Two types of lateral ribs present on the lateral surface of shell: type one having 14 numbers of ribs and extending from the nodules to the nucleus and type two having 12 numbers of ribs and extending up to halfway from the nodules. Shell having 20 prominent blunt paired nodules over the keel.

Colour: Background of the shell is brownish white in colour. Nodules are brownish black and a whitish shell coloured band running in-between the paired nodule on apertural view. Margin of ribs became white after

Figures

Figure 1. Argonauta hians Lightfoot, 1786: A. female in shell; B. Body of female; C – D. Lateral view of shell (both side); E. apertural view; F. abapertural view.

Figure 2. Map showing the recorded distribution of Argonauta hians Lightfoot, 1786 along Indian coast.