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1. Endosymbiotic relationship between gut microflora and lepidophagous fish, Neotropiuskhavalchor, Kulkarni Dr. Sanjay S. Kharat Modern College, Ganeshkhind, Pune, Maharashtra, India.

2. Lepidophagy • Fishes are grouped as herbivores, carnivores and omnivores on the basis of their food habit (Chakrabarti et al., 1995). • The consumption of various fish parts is a significant component of the trophic niche of several fish taxa. Among those body parts consumed, scales are probably the most common (Sazima, 1983). • Scale feeding, or lepidophagy, is defined as the ingestion of scales without bones or flesh (Sazima, 1983). • 5 freshwater families + 7 seven marine families have lepidophagous fishes.

4. Lepidophagous fishes and are known to have special oral morphology which supports their scale feeding habit (Peterson and Winemiller, 1997). • Sazima (1983) suggested that jaw structure and tooth placement determine the degree of lepidophagy. • Moreover, scales are made of the chitin, second most abundant polysaccharide in nature & resistance to the chemical degradation (Gooday, 1990; Gutowska et al., 2004). • But it assumed that it is rapidly degraded by the bacterial enzyme in the marine enzymes (Gooday, 1990). • Most of the study concerning the lepidophagy are only related to oral morphology and behavior but no study is done so far which provide in-depth information about the digestive physiology of these fishes.

5. Neotropius khavalchor, Kulkarni Fig. N. khavalchor Fig.Destribution In marathi, khaval= scales Chor=thief

6. Therefore, lepidophagy in N. khavalchor raises the possibility of presence of some kind of the specialized scale digestion mechanism probably in the form of bacterial gut flora to digest the chitin rich scales of prey animals.

7. Materials & methods

8. Results

9. Oral morphology & its suitability for lepidophagous nature in N. khavalchor • Strong dentition • Sub-terminal mouth • Upper jaw protruding over lower jaw • Upper jaw : Mollariform, blunt teeths directed outwards • Lower jaw: conical pointed villiform teeths, curved anteriorly Dentition Sub-terminal mouth Upper jaw Lower jaw

10. Pharyngeal Teeth Elongated, sharp villiform pharengeal teeth

11. Gut flora: qualitative, quantitative & morphological characterization Out of total 11 isolates only two were found to be chitinase positive (Named as a PNKS4 and PNKS5).

12. Molecular characterization of chitinase positive bacterial isolates

13. In-vitro scale degradation assay using B. pumilus & B. licheniformis Bacillus pumilus degraded 51.93% more scales; whereas Bacillus licheniformis degraded 49.20% more scales in comparison to the control group.

14. DiscussionCurrent work demonstrates gross anatomical features, feeding habit and endosymbiotic relationship between chitinolytic enzyme producing bacteria and N. khavalchor.

15. Dentition and distribution of teeth within oral cavity, its number and type in oral cavity are all diet related (Fishelson et al., 2014). • Presence of specialized oral morphology in N. khavalchor could be taken as a possible adaptation to the food type. • Elongated teeths on lower jaw: grasp & prevent the escape the small prey animals. • Flat teeths on upper jaw: to handle hard food stuff like scales. • Similar arrangement is found in carnivorous fish, Sparus aurata (El-Bakery, 2011).

16. Importance of Pharyngeal jaw teeth • Efficient crushing and processing of food items and thus freed the oral jaws from their dual task of food collection and preparation. • Perforations made by the villiform pharyngeal teeth, scale surface area also increases, which promote penetration of chitinase and enhance its degradation. • This could be additional strategy for gain the energy.

17. Diverse microbial community in the gastrointestinal tract of freshwater or marine fish species have been reported abundantly but their contribution in digestive process is not well investigated (Ray et al., 2012). • Chitinase producing endosymbiotic community is not yet documented in any fish species. • N. khavalchor is inhabited by two chitinase producing bacterial strains (B. pumilus & B. lichiniformis) which help them in digesting the chitinous scales (in-vitro assay). • Other bacterial genera which produce chitinases include Aeromonas, Serratia, Vibrio, Streptomyces and Bacillus (Kuddus et al., 2013).

18. Currently, N. Khavalchor is categorized as deta deficient species by IUCN therefore, other food sources used by this species apart from the scales is not yet known. • But chitinous scales might be used as a good sources of the energy by N. khvalchor. • Scales could be digested with the help chitinolytic bacteria present in the gut of N. khvalchor. • Future work needs to examine a broad diversity of fishes with varying feeding habits using comparable methodology.

19. Future directions • Handed Foraging Behavior in Scale-Eating Cichlid Fish. Adapted from: Lee et al., 2012, (PLoS ONE)

20. N. khavalchor do not have handedness, but it has a bilaterally symmetrical head. Foraging behavior? Attacking direction- left & right ?

21. Acknowledgements • BCUD, Savitribai Phule Pune University • Modern College staff and research scholars

22. Thank you