Start studying Biology Chapter 5 Section 3. Learn vocabulary, terms, and more with flashcards, games, and other study tools. A gill (/ ɡ ɪ l / ) is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water and excretes carbon dioxide.The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are kept moist.
| Snubnosed eel | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Anguilliformes |
| Family: | Synaphobranchidae |
| Genus: | Simenchelys T. N. Gill in Goode and Bean, 1879 |
| Species: | |
| Binomial name | |
| Simenchelys parasitica T. N. Gill in Goode and Bean, 1879 | |
| Synonyms | |
Conchognathus grimaldiiCollett, 1889 | |
The snubnosed eel, Simenchelys parasitica, also known as the pug-nosed eel, slime eel, or snub-nose parasitic eel, is a species of deep-sea eel and the only member of its genus. Some authors classify it as the sole member of the subfamily Simenchelyinae of the family Synaphobranchidae, or cutthroat eels, while others place it in its own monotypic family, the Simenchelyidae.[1] It is found in the Atlantic and Pacific Oceans, typically at a depth of 500–1,800 m (1,600–5,900 ft) near the bottom. Although typically a scavenger, it is better known for using its powerful jaws and teeth to burrow into larger fishes as a parasite.[2]
This species is harmless to humans and of no interest to fisheries.[2] The generic name Simenchelys translates literally as 'pug-nosed eel'.[3] In 2002, Koyama et al. reported that they had cultured cells from the pectoral fin of a snubnosed eel and maintained them in vitro for over a year. This represents one of the first cases of successful long-term tissue culture derived from a deep-sea multicellular organism, and has implications for a range of biotechnological fields.[4]
Distribution and habitat[edit]
In the eastern Atlantic, the snubnosed eel is known from France to Madeira and the Azores, as well as from off Cape Verde and South Africa. In the western Atlantic, it has been captured off the coast of the United States. In the Pacific, it occurs off Japan, Australia, New Zealand, and Hawaii. They have been recorded from 136 to 2,620 m (446 to 8,596 ft), but are usually found between 500 and 1,800 m (1,600 and 5,900 ft) on the continental slope, in water temperatures of 4–9 °C (39–48 °F).[2] At some locations, large numbers of snubnosed eels have been caught over a short time, indicating local abundance or schooling behavior.[5]
Description[edit]
The snubnosed eel has a long, stout body that is strongly compressed posterior of the vent. The head is thick and cylindrical, with a short, blunt snout. The mouth is distinctive, consisting of a tiny horizontal slit surrounded by strongly plicate lips. The jaws are short and strong, with the premaxillaries and maxillaries fused into a single piece. The jaws are equipped with a single row of small, rounded, close-set teeth; the vomerine teeth are absent. The eyes are small and round; the anterior pair of nostrils are short tubes and the posterior pair are slit-like. The gill openings are small and located below the pectoral fins, which are small and triangular. The dorsal, caudal, and anal fins are merged, the dorsal fin base originating over the tip of the pectoral fins and the anal fin originating behind the vent. The scales are similar in appearance to those of Anguilla and are arranged in a right-angle basketweave pattern. The coloration is gray to grayish brown, becoming darker at the fin margins and along the lateral line. This species attains a length of 61 cm (24 in).[2][3][6]
Biology and ecology[edit]
Early juvenile snubnosed eels feed on epibenthic copepods (Tharybis spp.) and amphipods.[7] Adults appear to be specialized hagfish-like scavengers, using their powerfully muscled jaws and short, stout teeth to tear away chunks of flesh from carcasses that have fallen to the sea floor.[8] However, this eel is more notorious for its parasitic habits, which are often repeated in literature. Frank Thomas Bullen, in the 1904 Denizens of the Deep, wrote that the eel 'attaches himself to the bodies of the larger, fleshier fish, such as halibut, and by sheer force of suction and boring withal works his ravenous way right into their bodies, at what misery to his involuntary hosts can only be imagined.'[9]Spencer Fullerton Baird reported that the eels are 'not unfrequently found nestling along the backbone of the halibut and cod, where they seem to have the power of abiding for some time without actually causing death.' Baird also made note of the eels' supposed habit of burrowing into the abdominal cavities of netted, gravidshad and eating their eggs within the span of 'a few minutes'.[10]
In 1992, two snubnose eels were discovered inside the heart of a 395 kg (871 lb) shortfin mako shark (Isurus oxyrhinchus) landed at Montauk, New York. The two eels, both immature females, measured 21 and 24 cm (8.3 and 9.4 in) long and had fed on blood, with histiological evidence suggesting that they had been there long enough for arteriosclerosis and hyperplasia (indicative of circulatory obstruction or toxicity from metabolic wastes), and tissue regeneration to occur. The authors speculated that the eels had burrowed into the shark through the gills or throat (the precise path of entry could not be determined, possibly obscured by damage caused by the tow rope) after it had been weakened on the capture line, entered the circulatory system, and then made their way to the heart. Despite records of its parasitic behavior, submersible encounters with free-swimming juveniles and adults, and their capture in baited traps, suggest that this species is at most a facultative parasite that opportunistically enters sick and dying fish.[5]
Reproduction is oviparous. The eggs are likely pelagic, measuring at least 2 mm (0.079 in) across, and lack an oil globule. An ovary from one 51 cm (20 in) female examined contained about 30,000 eggs. Like all other eels, the snubnosed eel undergoes a leptocephaluslarval stage that metamorphoses into a juvenile form resembling the adult. Leptocephali belonging to this species have yet to be identified, but based on the appearance of the metamorphic stage, they likely have long bodies with short heads and small mouths, and little to no body pigmentation. Metamorphic fish are white, with the black peritoneum clearly visible; one known metamorphic specimen measured 11 cm (4.3 in) long. Sexual maturation is attained at around a length of 50–53 cm (20–21 in).[7] The trematodeHypertrema ambovatum is a known parasite of this species, infesting the intestines.[5]
References[edit]
- ^Myers, P., Espinosa, R., Parr, C.S., Jones, T., Hammond, G.S. and Dewey, T.A. (2008). Simenchelyidae: PicturesArchived 2009-06-28 at the Wayback Machine. The Animal Diversity Web (online). Retrieved on March 6, 2009
- ^ abcdFroese, Rainer and Pauly, Daniel, eds. (2009). 'Simenchelys parasitica' in FishBase. March 2009 version. citing Saldanha, L. and M.-L. Bauchot, 1986. Synaphobranchidae (including Nettodaridae and Simenchelyidae). p. 586-592. In P.J.P. Whitehead, M.-L. Bauchot, J.-C. Hureau, J. Nielsen and E. Tortonese (eds.) Fishes of the north-eastern Atlantic and the Mediterranean. UNESCO, Paris. Vol. 2.
- ^ abJordan, D.S. & Evermann, B.W. (1896). The Fishes of North and Middle America: A Descriptive Catalogue of the Species of Fish-like Vertebrates Found in the Waters of North America, North of the Isthmus of Panama. Government Printing Office. ISBN0-665-24805-9.
- ^Koyama, S., Horii, M., Miwa, T. and Aizawa, M. (2003). 'Tissue culture of the deep-sea eel Simenchelys parasiticus collected at 1,162 m'. Extremophiles. 7 (3): 245–248. doi:10.1007/s00792-003-0317-8. PMID12768456.CS1 maint: multiple names: authors list (link)
- ^ abcCaira, J.N., Benz, G.W., Borucinska, J. and Kohler, N.E. (1997). 'Pugnose eels, Simenchelys parasiticus (Synaphobranchidae) from the heart of a shortfin mako, Isurus oxyrinchus (Lamnidae)'. Environmental Biology of Fishes. 49: 139–144. doi:10.1023/a:1007398609346.CS1 maint: multiple names: authors list (link)
- ^Smith, J.L.B. & M.M., and Heemstra, P. (2003). Smiths' Sea Fishes. Struik. ISBN1-86872-890-0.CS1 maint: multiple names: authors list (link)
- ^ abSolomon-Raju, N. & Rosenblatt, R.H. (June 1, 1971). 'New Record of the Parasitic Eel, Simenchelys parasiticus from the Central North Pacific with Notes on Its Metamorphic Form'. Copeia. 1971 (2): 312–314. doi:10.2307/1442833.
- ^Randall, D.J.; Farrell, A.D., eds. (1969). Deep-Sea Fishes. Academic Press. ISBN0-12-350440-6.[page needed]
- ^Bullen, F.T. (1904). Denizens of the Deep. F. H. Revell Company. ISBN0-659-90617-1.[page needed]
- ^Baird, S.F. (1889). The Sea Fisheries of Eastern North America. Government Printing Office.
Biology 11 Mrs N Gill Full
Research Interests
The trait improvement is the key for improving existing crop varieties and also for developing new superior varieties using molecular genetic approaches. My current research focus is on the identification of phenotype-by-genotype trait associations and transferring useful genes through marker-assisted background selection approach for crop improvement. We are using various types of genetic populations derived from multi-parental lines to identify novel genes/markers associated with desirable phenotypic traits.
Publications
Biology 11 Mrs N Gill Unit
Peer-reviewed International Journals
1. Gill KS, Kumar N, Randhawa HS, Carter AH, Yenish J, Morris CF, Baik B-K, Higginbotham RW, Guy SO, Engle DA, Chen XM, Murray TD, Lyon DJ (2020) Registration of ‘Mela CL+’ soft white winter wheat. Journal of Plant Registrations Doi.org/10.1002/plr2.20006.
2. Hinojosa L, Kumar N, Gill KS, Murphy KM (2019) Spectral reflectance indices and physiological parameters in quinoa under different irrigation regimes. Crop Science 59(5):1927.
3. Kumar N, Kiszonas A, Ibba MI, Morris CF (2019) Identification of molecular markers associated with super soft kernel texture in wheat. Journal of Cereal Science Doi.org/10.1016/j.jcs.2019.04.014.
4. Kumar N, Orenday-Ortiz Jose, Kiszonas A, Jr., Jeffrey B, Morris C (2019) Genetic analysis of a unique ‘super soft’ kernel texture phenotype in soft white spring wheat. Journal of Cereal Science 85: 162-167.
5. Kumar N, Randhawa HS, Higginbotham RW, Chen X, Murray T, Gill KS (2017) Targeted and efficient transfer of value-added genes into wheat variety. Molecular Breeding DOI: 10.1007/s11032-017-0649?1.
6. Rustgi S, Shafqat MN, Kumar N, Baenziger PS, Ali ML, Dweikat I, Campbell BT and Gill KS (2013) Genetic dissection of yield and its component traits using high-density composite map of wheat chromosome 3A: Bridging gaps between QTLs and underlying genes. PLoS One 8(7): e70526.
7. Mir RR, Kumar N, Girdharwal N, Jaiswal V, Prasad M, Balyan HS, Gupta PK (2012) Genetic dissection of grain weight in bread wheat through QTL interval and association mapping. Molecular Breeding 29:963?972.
8. Bennypaul HS, Mutti JS, Rustgi S, Kumar N, Okubara PA, Gill KS (2012) Virus-induced gene silencing (VIGS) of genes expressed in root, leaf and meiotic tissues of wheat. Functional & Integrative Genomics 12:143?156.
9. Lee H, Rustgi S, Kumar N, Burke IC, Yenish JP, Gill KS, von Wettstein D, Ullrich SE (2011) Single nucleotide mutation in the barley acetohydroxy acid synthase (AHAS) gene confers resistance to imidazolinone herbicides. Proceeding of the National Academy of Sciences USA 108:8909?8913.
10. Kumar J, Jaiswal V, Kumar A, Kumar N, Mir RR, Kumar S, Dhariwal R, Tyagi S, Khandelwal M, Prabhu KV, Prasad R, Balyan HS, Gupta PK (2011) Introgression of a major gene for high grain protein content in some Indian bread wheat cultivars. Field Crops Research 123:226?233.
11. Kumar J, Mir RR, Kumar N, Kumar A, Mohan A, Prabhu KV, Balyan HS, Gupta PK (2010) Marker-assisted selection for pre-harvest sprouting tolerance and leaf rust resistance in bread wheat. Plant Breeding 129:617?6211.
12. Kumar N, Roy JK, Kulwal PL, Balyan HS, Gupta PK (2009) QTL analysis for growth related traits in inter-varietal mapping population of common wheat. Journal of Genetics and Breeding 61:30?38.
13. Gupta PK, Balyan HS, Kulwal P, Kumar N, Kumar A, Mir R, Mohan A, Kumar J (2007) QTL analysis for some quantitative traits in bread wheat. Journal of Zhejiang University Science B 8:807?814.
14. Kumar N, Kulwal PL, Balyan HS, Gupta PK (2007) QTL mapping for yield and yield contributing traits in two mapping populations of bread wheat. Molecular Breeding 19:163?177.
15. Kumar N, Kulwal PL, Gaur A, Tyagi AK, Khurana JP, Khurana P, Balyan HS, and Gupta PK (2006) QTL analysis for grain weight in common wheat. Euphytica 151:135?144.
16. Kumar N, Balyan HS, Gupta RK, Gupta PK (2006) Genetic analysis of grain protein content in bread wheat. Journal of Genetics and Breeding 60:29?36.
17. Singh R, Kumar N, Bandopadhyay R, Rustgi S, Sharma S, Balyan HS, Gupta PK (2006) Development and use of anchored-SSRs to study DNA polymorphism in bread wheat. Molecular Ecology Notes 6:296?299.
18. Balyan HS, Gupta PK, Kulwal PL, Kumar N (2006) QTL analyses for three grain quality traits in bread wheat using intervarietal mapping populations. Czech Journal of Genetics and Plant Breeding 41:281?283.
19. Balyan HS, Gupta PK, Rustgi S, Bandopadhyay R, Goyal A, Singh R, Kumar A, Kumar N, Sharma S (2006) Development and use of SSRs of bread wheat for genetic and physical mapping and transferability to the species of Triticum-Aegilops complex. Czech Journal of Genetics and Plant Breeding 41:141?144.
20. Gupta PK, Rustgi S, Kumar N (2006) Genetic and molecular basis of grain size and grain number and its relevance to grain productivity in higher plants. Genome 49:565?571.
21. Kulshreshtha R, Kumar N, Balyan HS, Gupta PK, Khurana P, Tyagi AK, Khurana JP (2005) Structural characterization, expression analysis and evolution of the red/far-red sensing photoreceptor gene, PHYTOCHROME C (PHYC), localized on the ‘B’ genome of hexaploid wheat (Triticum aestivum L.). Planta 221:675?689.
22. Kulwal PL, Kumar N, Gaur A, Khurana P, Khurana JP, Tyagi AK, Balyan HS, Gupta PK (2005) Mapping of a major QTL for pre-harvest sprouting tolerance on chromosome 3A in bread wheat. Theoretical and Applied Genetics 111:1052?1059.
23. Kulwal PL, Kumar N*, Kumar A, Gupta RK, Balyan HS, Gupta PK (2005) Gene networks in hexaploid wheat: interacting quantitative trait loci for grain protein content. Functional & Integrative Genomics 5:254?259 [*Equally Contributed].
24. Gupta PK, Rustgi S, Sharma S, Singh R, Kumar N, Balyan HS (2003) Transferable EST-SSR markers for the study of polymorphism and genetic diversity. Molecular Genetics and Genomics 270:315?323.
25. Prasad M, Kumar N, Kulwal PL, Röder M, Balyan HS, Dhaliwal HS, Gupta PK (2003) QTL analysis for grain protein content using SSR markers and validation of associated markers using NILs in bread wheat. Theoretical and Applied Genetics 106:659?667.
26. Kumar S, Kumar N, Balyan HS, Gupta PK (2003) 1BL.1RS translocation in some Indian bread wheat genotypes and strategies for its use in future wheat breeding. Caryologia 56:23?30.
27. Sharma S, Balyan HS, Kulwal PL, Kumar N, Varshney RK, Prasad M, Gupta PK (2002) Study of inter-specific SSR polymorphism among 14 species from Triticum-Aegilops group. Wheat Information Service 95:23?28.
28. Varshney RK, Prasad M, Roy JK, Kumar N, Singh H, Dhaliwal HS, Balyan HS, Gupta PK (2000) Identification of eight chromosomes and a microsatellite marker on 1AS associated with QTL for grain weight in bread wheat. Theoretical and Applied Genetics 100:1290?1294.
Book Chapters
29. Kumar N*, Rustgi S (2013) Agronomically relevant traits transferred to major crop plants by alien introgressions. In: Pratap A, Kumar J (Eds.), Alien Gene Transfer in Crop Plants, Innovations, Methods and Risk Assessment (Vol. I) Springer, New York, USA, ISBN: 978?1?4614?8584?1, P211. [*Equally Contributed & Corresponding Author].
Products as Wheat Varieties:
30. Gill KS, Kumar N, Carter A, Randhawa HS, Morris C, Baik B, Higginbotham R, Engle D, Guy S, Murray TD, Burke I, Lyon D, Chen X (2013) Developed two-gene Clearfield soft white common winter variety ‘Curiosity CL+’ using marker assisted background selection approach. Released in October 1st, 2013.
31. Gill KS, Kumar N, Carter A, Randhawa HS, Morris C, Baik B, Higginbotham R, Engle D, Guy S, Murray TD, Burke I, Lyon D, Chen X (2013) Developed two-gene Clearfield soft white common winter wheat variety ‘Mela CL+’ using marker assisted background selection approach. Released in October 1st, 2013.
32. Gill KS, Kumar N, Randhawa HS, Murphy K, Carter A, Morris C, Higginbotham R, Engle D, Guy S, Drew L, Murray TD, Chen X, Schillinger W (2016) Developed two-gene Clearfield soft white common winter variety ‘Resilience CL+’ using marker assisted background selection approach. Released in October 1st, 2016.
Non-peer Reviewed Publications
33. Morris CF, Kumar N, Ibba MI, Kiszonas AM, Orenday-Ortiz J (2019) 'Super Soft' wheat kernel texture-Where does it come from? Abstract submitted in Ist International Wheat Congress, Saskatoon, July 21-26th, Saskatchewan, Canada.
34. Balyan HS, Varshney RK, Roy JK, Prasad M, Kulwal PL, Kumar N, Rustgi S, Kumar A, Mir RR (2016) From development of molecular markers to marker-assisted breeding: a successful journey. In: Balyan HS (editor) A tribute to Professor PK Gupta: Legendary Teacher and Scholar Ch. Charan Singh University, Meerut. December 14?16th, 2016, P54.
35. Kumar J, Kulwal PL, Kumar N, Mir RR, Kumar A, Prabhu KV, Balyan HS, Gupta PK (2008) Marker assisted selection for improvement of grain protein content and pre-harvest sprouting tolerance in bread wheat. Published in International Conference on Molecular Biology & Biotechnology October 19-21th, 2008.
36. Mir RR, Mohan A, Kumar N, Kulwal PL, Prasad M, Girdharwal N, Kumar V, Singh R, Kumar J, Balyan HS, Gupta PK (2008) Genome-wide QTL analysis for grain weight and pre-harvest sprouting in bread wheat. Published in International Conference on Molecular Biology & Biotechnology October 19-21.
37. Mir RR, Kumar N, Prasad M, Girdharwal N, Kumar J, Balyan HS, Gupta PK (2008) Single-locus and two-locus QTL analysis to detect main effect and epistatic QTL for grain weight in bread wheat. In: Appels R, Estwood R, Lagudah E, Lengridge P, Lynne MM, (editors), proceedings XI International Wheat Genetics Symposium, Sydney University Press, Brisbane, Australia.
38. Gupta PK, Balyan HS, Kumar J, Kulwal PL, Kumar N, Mir RR, Kumar A, Mohan A (2008) QTL analysis and marker assisted selection for improvement in grain protein content and pre-harvest sprouting tolerance in bread wheat, In: Appels R, Estwood R, Lagudah E, Lengridge P, Lynne MM, (editors), proceedings XI International Wheat Genetics Symposium, Sydney University Press, Brisbane, Australia.
39. Gupta PK, Balyan HS, Bandopadhyay R, Kumar J, Mohan A, Kumar N, Kulwal PL, Rustgi S, Singh R, Goyal A, Kumar A, Kumar V, Girdharwal N, Rouf Mir R (2006) Development and use of molecular markers for wheat genomics and breeding, Annual Wheat Newsletter 52: 43?46.
40. Gupta PK, Balyan HS, Bandopadhyay R, Kumar N, Sharma S, Kulwal PL, Mohan A, Rustgi S, Singh R, Goyal A, Kumar A (2005) Development and use of molecular markers for wheat genomics, Annual Wheat Newsletter 51:51?55.
41. Gupta PK, Balyan HS, Bandopadhyay R, Kumar N, Sharma S, Kulwal PL, Rustgi S, Singh R, Goyal A, Kumar A (2004) Development and use of molecular markers for wheat genomics. Annual Wheat Newsletter 50: 52?56.
42. Gupta PK, Balyan HS, Prasad M, Roy JK, Bandopadhyay R, Kumar N, Sharma S, Kulwal PL, Rustgi S, Singh R, Goyal A, Kumar A, Prashanth SN (2003) Development and use of molecular markers for QTL mapping and genomics research in bread wheat. Annual Wheat Newsletter 49: 42?46.
43. Gupta PK, Balyan HS, Kumar S, Prasad M, Roy JK, Kumar N, Sharma S, Kulwal PL, Rustgi S, Singh R (2002) Development and use of molecular markers for genetic mapping and marker-assisted selection (MAS) in wheat. Annual Wheat Newsletter 48:76?80.
44. Gupta PK, Balyan HS, Prasad M, Roy JK, Kumar N, Sharma S, Kulwal PL (2001) Marker assisted selection for some quality traits in bread wheat. Annual Wheat Newsletter 47:68?72.