Krohnitta subtilis   (Grassi,  1881) (Marine Worm)
Organism information awaits expert curation
Class: Sagittoidea

Image copyrights: McLelland, JA and Michel, HB

Size: Total length 12-16 mm; Tail 30-40% of the total body length.

The body is long, thin, transparent and floppy. Eyes round with T-shaped pigment spot. On either side of the small head there are 6-9 strong hooks and 10-13 very prominent teeth in a single row covering the anterior of the head. No collarette or gut diverticula present. The single pair of broad lateral fins begins at a point between two thirds and half the distance between the ventral ganglion and the caudal septum. One third of their length is on the trunk and they are wide and semicircular in shape, almost totally without rays. The rays are short and wide apart. Lack of supportive rays means these fins are often badly damaged.

The seminal vesicle touches both the lateral and tail fins. The ovaries are short, reaching the anterior end of the lateral fins. The large ova are in two dorsoventral rows.

Synonym (s)
Eukrohnia subtilis Michael, 1911

Common Name (s)
Economic Importance and Threats

Habitat:  Pelagic, Reef Associated


• Karnataka, Netrani Island (Lat: 14.01) (Long: 74.32) INDIA (Record: 10/05/2006)
• Tamil Nadu, Chennai Coast INDIA
• Kerala, Kochi INDIA
• Kerala, Alleppey INDIA
• Kerala, Paravur INDIA
• Kerala, Kayamkulam INDIA
• Kerala, Neendakara INDIA
• Kerala, Veli INDIA
• West Coast INDIA
• Tamil Nadu, Gulf of Mannar INDIA (Record: 01/1955-12/1958)
• Palk Bay INDIA (Record: 01/1955-12/1958)

Literature Source(s)
  • Alfred, JRB; Das, AK and Sanyal, AK (Eds.) (1998) Faunal diversity in India ZSI, Calcutta 1-497 Available at - NCL, Pune
  • Venkatraman, K; Srinivasan, M; Satyanarayana, CH and Prabhakar D (2002) Faunal diversity of Gulf of Mannar biosphere reserve Conservation area series 15 ZSI 77 pp; VIII pla Available at - NCL, Pune
  • Nair, VR Chaetognatha NIO, Goa Available at -
  • Conway, DVP; White, RG; Hugues-Dit-Ciles, J; Gallienne, CP and Robins, DB (2003) Guide to the coastal and surface zooplankton of the south western Indian Ocean Occasional publication no 15 Marine Biological Association of the United Kingdom Occasional Publication of the Marine Biological association of the United Kingdom 354 pp Available at -
  • Michel, HB; Behbehani, M; Herring, D; Arar, M; Shoushani, M and Brakoniecki T (1986) Zooplankton diversity, distribution and abundance in Kuwait waters Kuwait Bulletin of Marine Science 8 37-105 Available at - Zoological records
  • Zacharia, PU; Krishnakumar, PK; Dineshbabu, AP; Vijayakumaran, K; Rohit, P; Thomas, S; Sasikumar, G; Kaladharan, P; Durgekar, RN and Mohamed, KS (2008) Species assemblage in the coral reef ecosystem of Netrani Island off Karnataka along the southwest coast of India Journal of the Marine Biological Association of India The Marine Biological Association of India, Cochin, India 50(1) 87-97 Available at - NIO, Goa
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • McLelland, JA and Michel, HB Interactive key to the species of Chaetognatha from the south Atlantic Bight and northern Gulf of Mexico Southeastern regional taxonomic center: Taxonomic information Available at -
  • Sealifebase Available at -
  • Dr. Ramesh, R; Dr. Nammalwar, P and Dr. Gowri, VS (2008) Database on coastal information of Tamil Nadu Report Submitted to Environmental Information System (ENVIS) Centre, Department of Environment, Government of Tamil Nadu Institute for Ocean Management, Anna University, Chennai, Tamil Nadu. Available at -
  • Robin, RS; Srinivasan, M and Chandrasekar, K (2009) Distribution of Zooplankton from Arabian Sea, along Southern Kerala (Southwest Coast of India) During the Cruise Current Research Journal of Biological Sciences Maxwell Scientific Organization 1(3) 155-159 Available at -
  • Srinivasan, M (1947) Distribution of chaetognaths,with special reference to Sagitta decipiens as an indicator of upwelling along the west coast of India Journal of the marine biological association of India The marine biological association of India 16(1) 126-142 Available at -
  • Sudarsan, D (1961) Observations on the chaetognatha of the waters around Mandapam Indian Journal of Fisheries Indian Council of Agricultural Research 8 (2) 364-382 Available at -

Page last updated on:2011-05-31

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