This article was downloaded by: [Institute of Zoology] On: 13 December 2013, At: 23:59 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Italian Journal of Zoology Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tizo20 Surface ultrastructure of the olfactory epithelium of loach fish, Triplophysa dalaica (Kessler, 1876) (Cypriniformes: Balitoridae: Nemacheilinae) B. Waryani a b c , R. Dai a , Y. Zhao b , C. Zhang b & A. R. Abbasi c a School of Life Sciences, Beijing Institute of Technology b Key Laboratory of Zoological Systematic and Evolution , Chinese Academy of Sciences c Department of Fresh Water Biology and Fisheries , University of Sindh Jamshoro , Pakistan Published online: 20 Mar 2013. To cite this article: B. Waryani , R. Dai , Y. Zhao , C. Zhang & A. R. Abbasi (2013) Surface ultrastructure of the olfactory epithelium of loach fish, Triplophysa dalaica (Kessler, 1876) (Cypriniformes: Balitoridae: Nemacheilinae), Italian Journal of Zoology, 80:2, 195-203, DOI: 10.1080/11250003.2013.771711 To link to this article: http://dx.doi.org/10.1080/11250003.2013.771711 PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. 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ABBASI3 1School of Life Sciences, Beijing Institute of Technology, 2Key Laboratory of Zoological Systematic and Evolution, Chinese Academy of Sciences, and 3Department of Fresh Water Biology and Fisheries, University of Sindh Jamshoro, Pakistan (Received 11 January 2012; accepted 19 January 2013) Abstract The olfactory organs of loach Triplophysa dalaica were examined under a scanning electron microscope, sampled from the Dali-Nor Lake, Inner Mongolia, China. The olfactory organs are oval in shape, lying in the olfactory chamber on the dorsal side of the head. Ten pairs of lamellae in the rosette are present on each side of the middle raphe. Lamellae are covered with cilia at some margins. The surface of the olfactory lamellae is divided into three epithelial regions: sensory, ciliate non-sensory and non-ciliated non-sensory epithelium. Sensory epithelium consists of receptors and supporting cells, ciliated non-sensory epithelium is covered with dense cilia and non-receptor epithelium is covered with ciliated stratified epithelial cells and mucus cells. Cells other than epithelial cells present on the surface of the rosette are related to the significant olfactory function in the fish concerned. Keywords: Loach, olfactory epithelium, electron micrograph, scanning electron microscope, histology Introduction organs were focused on macro- or micro-observation of their structure for comparative anatomies within In most fishes, olfactory organs are present on the a taxonomic context (Pfeiffer 1964; Su & Li 1982). anterior dorsal side of the head. Olfactory organs Goniakowska-Witalinska et al. (1992, 1995) stud- are composed of olfactory rosettes, bulbs, lobes, ied the neuroendocrine cells in gills of bowfin and nerves and receptors of smell and touch. Externally in the lung of tiger salamander. The studies show they are connected with nasal openings and function the relatively complex pattern of the neuroendocrine in prey location, migration, propagation, shoaling cells. They found that the neuroendocrine cells in and species recognition (Song 1987). Olfaction is Downloaded by [Institute of Zoology] at 23:59 13 December 2013 the gill epithelium of Amia and lung of Ambystoma achieved mainly by olfactory cells on the surface of tigrinum are of unusual type both ultrastructurally lamellae (Ichikawa & Ueda 1977; Hansen & Zeiske and immunocytochemically. With advanced tech- 1998). Water contains dissolved chemicals, which niques for observation at the cellular level, the flow into the olfactory sac through the nostril infil- emphases have been centered on the study of mor- trate by cell reactions of the olfactory cells (Fishelson phology, structure and physiology of the olfactory 1995). In different groups of fishes there are varia- organ and its ecological adoptability (Banerjee 1993; tions in the ratio of the length of the olfactory sac to Giorgi et al. 1994; Wang et al. 1994; Fishelson eye diameter, the number of lamellae on the olfactory 1995; Liu et al. 2005; Ma et al. 2005). A number organ and the arrangement of olfactory cells of of studies have been carried out on the size of the the epithelium in sensory and non-sensory areas olfactory structures relating to species ecology, which (Yamamoto 1982; Meng et al. 1987; Bandyopadhyay indicates that differences in the size of olfactory & Datta 1998). Earlier studies on the olfactory structures are directly related to olfactory sensitivity *Correspondence: Z. Chunguang, Institute of Zoology, Chinese Academy of Sciences National Zoological Museum, Key Laboratory of Zoological Systematics and Evaluation, Chinese Academy of Sciences, No.1-5, Beichen West Road, Chaoyang District, Beijing, 100101, P.R. China. Tel: +86 010-64807116. Fax: +86 010-64807116. Email: fi[email protected] © 2013 Unione Zoologica Italiana 196 B. Waryani et al. (Northcutt 1977, 1978; Theisen et al. 1986; Lisney Histological studies & Collin 2006; Lisney et al. 2007; Yopak et al. 2007; Olfactory tissues were immersed in aqueous Bouin’s Schluessel et al. 2008; Theiss et al. 2009). solution for a period of 20 hours for fixation. Fixed Loach, Triplophysa dalaica (Kessler, 1876) tissues were washed in distilled water, repeatedly (Cypriniformes: Balitoridae: Nemacheilinae), is a rinsed in 70% ethanol and dehydrated through a benthic fish found in slow running or standing water, graded series of ethanol followed by acetone and that feeds upon aquatic invertebrates (Kessler 1876; cleared in benzene. The tissues were embedded in Zhu 1989). Zhang et al. (1994) conducted studies paraffin wax at 56–58◦C under thermostat vacuum on the surface ultrastructure of gills, olfactory paraffin-embedding bath for a period of 1.5 hours. organs and barbells of Triplophysa (Hedinichthys) Sections were obtained using a rotary microtome. yarkandensis yarkandensis. Loach, T. dalaica,isa The sectioned tissues were stretched on Mayer’s freshwater fish species but it can tolerate living albuminised glass slide and stained with eosinhaema- in saline waters as well. No significant work has toxylin stain. Stained slides were examined and pho- appeared in the literature relating to the olfactory tographed under a Zeiss W-Pl 10 ×/23 compound organ of Loach living in saline waters. microscope. Loach, T. dalaica, living in saline water of Dalai- Nor Lake in Inner Mongolia, China was selected for the present study. The present work explores the Results changes on the surface of the olfactory organ. This Figure 1a–c shows the structure of the complete paper describes the detailed morphology and struc- fish Triplophysa dalaica; the head region shows the ture of the olfactory organ of T. dalaica using optical anterior and posterior olfactory openings and dis- and scanning electron microscopy and is the first sected head from the dorsal side, which shows the research report on the microstructure of the olfactory complete olfactory organ lying in the chambers. organ of this species. Paired olfactory rosettes are situated on the anterior dorsal side of the head in olfactory pits or olfactory Materials and methods chambers (Figure 1b). Externally, each pit has two Fish samples were collected in July 2010 from Dalai- separate openings, anterior and posterior, present Nor Lake (43.97◦N, 117.47◦E), the second largest on both sides of the head. Anterior and posterior lake in Inner Mongolia, China. The lake is located nostrils are close to each other. Both nostrils are north of Beijing at a distance of 200 km. Fish sam- oval in shape; the posterior nostril is wider than the ples were preserved in 10% formalin and brought to anterior nostril. A prominent flap of skin called the the Zoological Museum of the Institute of Zoology, nasal flap is present between the anterior and poste-