A first record of the benthic form of Stylocheiluslongicauda (Quoy & Gaimard, 1824) (Anaspidea: Aplysiidae) from Gujarat and Maharashtra along the mainland west coast of India

 

Deepak Apte

 

Bombay Natural History Society, Hornbill House, Opposite Lion Gate, Dr. SalimAli Chowk, Shaheed Bhagat Singh Road, Mumbai, Maharashtra 400001, India

spiderconch@gmail.com

 

 

 

doi: http://dx.doi.org/10.11609/JoTT.o3219.5299-300  | ZooBank:urn:lsid:zoobank.org:pub:798C5029-099F-4331-A0B5-BC9C6D565834

 

Editor: Basudev Tripathy, Zoological Survey of India, New Alipore, India.           Date of publication: 26 December 2013 (online & print)

 

Manuscript details: Ms # o3219 | Received 27 May 2012 | Final received 17 November 2013 | Finally accepted 21 November 2013

 

Citation: Apte, D. (2013).A first record of the benthic form of Stylocheilus longicauda (Quoy & Gaimard, 1824) (Anaspidea: Aplysiidae) from Gujarat and Maharashtra along the mainland west coast of India. Journal of Threatened Taxa 5(17): 5299–5300; http://dx.doi.org/10.11609/JoTT.o3219.5299-300

 

Copyright: © Apte 2013. Creative Commons Attribution 3.0 Unported License. JoTT allows unrestricted use of this article in any medium, reproduction and distribution by providing adequate credit to the authors and the source of publication.

 

Funding: The author is grateful to the Ministry of Environment and Forest for providing funds through AICOPTAX-Mollusca.

 

Competing Interest: None.

 

Acknowledgements: The author expresses thanks to Vishal Bhave, Reshma Pitale,Pooja Nagale, Amruta Prasade, Vishwas Shinde and Rajendra Pawar for assistance in the fieldwork for AICOPTAX-Mollusca.

 

 

 

For images -- click here

 

Stylocheilus longicauda (Quoy & Gaimard 1824) is a relatively small Sea Hare belonging to the family Aplysiidae.  The species is widely distributed and circum-tropical (Indo-West Pacific & Atlantic) in distribution.  It has been reported from India in the past from Lakshadweep (Apte 2009) and the Andaman group of islands (Sachithanandam et al. 2011) reported as Stylocheilus striatus (Quoy & Gaimard, 1832) which is now redesignated as the benthic form of Stylocheilus longicauda (Quoy & Gaimard, 1824) by Yonow in 2012.

The species is seasonally abundant; large congregations being common between October and March (Apte2009; Yonow 2012).  A significant feature of the animal is the longitudinal lines running across the body and scatteredeye spots, either with pink or blue.  The animal feeds on blue-green algae which form a mat or film over rocks or the surface of muddy and sandy shores (Yonow 2012).  Like all aplysiidspecies, when disturbed, the animal releases a purple fluid from its body as an escape strategy (Bebbington 1974).  The benthic form of Stylocheilus longicauda is usually seen in sea grass or seaweed beds (Yonow2012).

Study site: The study was carried out at Ambolgad in Ratnagiri District of Maharashtra and Okhain the Gulf of Kachchh, Gujarat.

(a) Ambolgad is located (16038’33.51”N & 73019’20.57”E) on the west coast of India (Ratnagiri District) of Maharashtra along the Arabian Sea.  Patchy reefs are present in the intertidal areas and occasionally at the sub-tidal depths.  The shore at Ambolgadis dominated with numerous shallow rock pools.

(b) Okha is located (22029’7.62”N & 6904’1.31”E) in the state of Gujarat on the same west coast of India.  The habitat is dominated by a rocky shore with abundant algal growth.  The Gulf of Kachchh and the Marine National Park in and around Okha is known for its abundance of various species of corals and mollusca.

Duration of the study: On going work from April 2005 till date under AICOPTAX.

Materials and Methods: The direct search method was used to find the opisthobranchs by turning over rocks and boulders in the inter-tidal region.  A few specimens were collected from each site and preserved in 95% ethyl alcohol and deposited in the Bombay Natural History Society (BNHS) opisthobranch collection.

Results: During the field work on 13 November 2009 along the Gulf of Kachchh, the author came across eight specimens of opisthobranchs on the rocky shore of Okha in Gujarat (Image 2).  Again on 21 March 2012, a congregation of 77 individuals was observed in the shallow rock pool at Ambolgad in Maharashtra (Image 3).

Size: The specimens studied in the present work ranged from 55–80 mm at Ambolgad while specimens from Okha ranged from 30–35 mm.  These are known to grow up to 30mm.  Rudman (1999) however reported animals from Zanzibar growing up to 65mm.  Apte (2009) reported 30mm specimens from Lakshadweep (Image 1).  The size of the specimens seen at Ambolgad is the largest among all the known records from India.

The present record of the benthic form of S. longicaudafrom Okha in Gujarat and Ambolgadin Maharashtra is the first record from the mainland west coast of India.

 

 

References

 

Apte, D.A. (2009). Opisthobranch fauna of Lakshadweep Islands, India with 52 new records to Lakshadweep and 40 new records to India. Part 1. Journal of the Bombay Natural History Society 106(2): 162–175.

Bebbington, A. (1974). Aplysiidspecies from East Africa with notes on the Indian Ocean Aplysiomorpha(Gastropoda: Opisthobranchia). Zoological Journal Linnaean Society 54(1): 63–99; http://dx.doi.org/10.1111/j.1096-3642.1974.tb00793.x 

Yonow, N. (2012). Opisthobranchs from the western Indian Ocean, with descriptions of two new species and ten new records (Mollusca: Gastropoda). ZooKeys 197: 1–130; http://dx.doi.org/10.3897/zookeys.197.1728 

Sachithanandam, V., P. Dhivya, P.M. Mohan, P. Muneeswaran & R. Baskaran (2011). First record of Stylochelius striatus (Mollusca: Gastropoda:Anaspidea: Aplysiidae) from the Andaman Sea, India. Journal of Oceanography and Marine Science 2(8): 165–167.

Rudman, W.B. (1999). (August 5) Stylocheilus striatus (Quoy& Gaimard, 1832). [In] Sea Slug Forum. Australian Museum, Sydney. Available fromhttp://www.seaslugforum.net/factsheet/stylstri