Diskussion:Schwarzband-Sägesalmler
Abschnitt Systematik
[Quelltext bearbeiten]Der dt. Name Schwarzband-Sägesalmler wird hier [1] und [2] erwähnt.
Der Abschnitt Systematik ist extrem verwirrend und für mich selbst nicht verständlich. Wer kann das vielleicht besser erläutern? Gruss, --Graf zu Pappenheim 06:46, 2. Feb. 2011 (CET)
- Du solltest es unterlassen Abschnitte zur Systematik zu verfassen, wenn du es selbst nicht verstehst. Ein Artikel braucht nicht unbedingt einen Systematikteil. Serrasalmus maculatus und Serrasalmus nigricans sind gültige Arten und keine Synonyme. Nachschauen bei Fishbase hätte genügt. Wikipedia hat zu wenig Leute um immer alles zu überprüfen. Den Systematikteil werde ich löschen. Gruß,--Haplochromis 07:19, 2. Feb. 2011 (CET)
Hallo Haplochromis, mit dem Unterabschnitt Systematik versuche ich die Art einzuordnen, die historische Entwicklung des Taxons darzustellen und einen Bezug zur jeweiligen Gattung herzustellen, mehr eigentlich nicht. Bei Serrasalmus nigricans (oder doch P. nigricans?) hast Du recht, es ist tatsächlich eine eigenständige Art: Serrasalmus nigricans (http://www.angelfire.com/biz/piranha038/nigricans.html)
„Messr. Jégu considers this species (Jégu in Reis et al. 2003) valid as Serrasalmus nigricans. There are no types known. There are some serious problems with this species based on Fink 1993. In my opinion, hobbyist/collectors are cautioned against using this scientific name on their fish if it comes from the locality mentioned below. Photos seen in some published hobbyist books purported to be S. nigricans are those of Pygocentrus nattereri. Pygocentrus nigricans, from "Equatorial Brazil," described by Agassiz (in Spix and Agassiz, 1829) as a Serrasalmo. This is indeed a Serrasalmus, the Amazonian form equivalent to Serrasalmus spilopleura in the south of Brazil, as the original plate (XXX) clearly shows. The name nigricans was used by Müller and Troschel (1845) in a new combination (their new genus Pygocentrus). The specimen they considered to be nigricans is actually P. nattereri and is held in the Berlin Museum (ZMB 3630). Müller and Troschel gave no evidence that the specimen they examined was the type of Agassiz's nigricans, and the specimen has dorsal-and anal-fin counts slightly different from those reported by Agassiz. In addition to the evidence of its identity from the well-done figure, as noted above, the description of live color in nigricans accurately describes the breeding adult of the Amazonian Serrasalmus, mitigating against placement of this species in Pygocentrus. Amazon river basin, Brazil. Dr. William L. Fink - Revision of genus Pygocentrus: Pygocentrus nigricans, from "Equatorial Brazil," described by Agassiz (in Spix and Agassiz, 1829) as a Serrasalmo. This is indeed a Serrasalmus, the Amazonian form equivalent to spilopleura in the south of Brazil, as the original plate (XXX) clearly shows. The name nigricans was used by Müller and Troschel (1845) in a new combination (their new genus Pygocentrus). The specimen they considered to be nigricans is actually P. nattereri and is held in the Berlin Museum (ZMB 3630). Müller and Troschel gave no evidence that the specimen they examined was the type of Agassiz's nigricans, and the specimen has dorsal-and anal-fin counts slightly different from those reported by Agassiz. In addition to the evidence of its identity from the well-done figure, as noted above, the description of live color in nigricans accurately describes the breeding adult of the Amazonian Serrasalmus, mitigating against placement of this species in Pygocentrus (Fink, 1993). Serrasalmus nigricans: Spix, J. B. von and L. Agassiz 1829-31 Selecta genera et species piscium quos in itinere per Brasiliam annos MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I.... colleget et pingendso curavit Dr J. B. de Spix.... Monachii. Selecta Piscium Brasiliam: Part 1: i-xvi + i-ii + 1-82, Pls. 1-48;, Part 2: 83-138, Pls. 49-101. [Part 1 published June 1829, part 2 Jan. 1831; see Kottelat 1988 [ref. 13380], Whitehead & Myers 1971, Pethiygoda & Kottelat 1998 [ref. 23896]. No types known Equatorial rivers of Brazil. No types known. (Fink 1993) Valid as Serrasalmus nigricans Spix & Agassiz 1829 (Jégu in Reis et al. 2003, with author as Agassiz. Distribution: Amazon R. basin, Brazil...“
Auch bei Fishbase wird sie genannt: [3] Serrasalmus nigricans (Spix & Agassiz, 1829. Erwähnt werden sollte S. nigricans auf jeden Fall (im Artikel Piranhas), für einen eigenen Artikel gibt es wahrscheinlich zu wenige Infos. Gruss, --Graf zu Pappenheim 03:07, 12. Feb. 2011 (CET)
- What at all in heaven ... »angelfire-com« ist doch KEINE Quelle! Natürlich ist Serrasalmus nigricans (Spix & Agassiz 1829) valide. So was muss einem Autor seriös belegt klar sein, BEVOR er einen Artikel beginnt. Gruß, Lohachata 07:34, 12. Feb. 2011 (CET)
Biologische Aspekte
[Quelltext bearbeiten]Wie kann man diese Textpassagen vernünftig einbauen, die Kernaussagen sind für mich unklar:
The present paper is about biological aspects of the piranha Serrasalmus spilopleura studied in the Sanchuri barrage, in Uruguaiana County, Rio Grande do Sul State, Brazil (29º35’06”S and 56º50’54”W). The total amount of specimens was 949 and 495 were actually used for this study, were 80.6% of which adults, 13.53% sub-adults and 5.85% juveniles. Local physical and chemicals data such as temperature of the air and water, dissolved oxygen, nitrite and nitrate, pH, electric conductivity of the water and monthly photoperiod average were collected and presented. Linear regression between mouth width and standard length (Ls) of males (b=1.281) and females (b=1.116) was performed in order to associate the size of the injuries with the size of predators and preys.
A standard intra-species injury was observed in 53.92% of all specimens analyzed (44.77% females; 55.22% males) that had significance in terms of season, size predators and areas injured. These standard injuries were due to the recruitment time and to the maturity classes juvenile and subadult. At the same time, predators and lethal intra-species injuries by adults of S. spilopleura were not observed among the collection. A general analysis of aspects of inter-species predators was also done. Identification and discrimination of the disposition of the teeth occluded in the jaw and their substitution was performed too.
As for feeding, the repletion index and the repletion stages were obtained were the c2 test (P<0,05) was applied to provide the level of significance between them. The species gets food all year long, with more intensity during spring and in smaller amounts during the winter. The numeric occurrence test (ON) and the test of occurrence of frequency (f) of the alimentary items indicated a basically carnivore and ichthyophagous diet, with a special place for insects in December. The length-weigh relationship identified a small positive allometric growth (b) (males=3.164; females=3.211). The condition variability factor (DK) indicated different ways to males and females, where males are associated to alimentary periods and females to the reproductive cycle.
The hepatossomatic index (IHS) indicated the smallest levels in February for both sex, corroborating the feeding analyses. The annual average sexual proportion of the population was 0.97 (F:M), being January and March was 1.8 (F:M) for adults only. The average lenght in the beginning of the gonadal maturation (L50) indicated that S. spilopleura was able to reproduce at 140mm Ls (females) and 150mm Ls (males); and that the average lenght in winch all the individuals are capable to reproduce (L100) was 150mm Ls (females) and 170mm Ls (males). The reproductive period was determined, through macroscopic analysis of the gonadal maturity stages and variability of the gonadossomatic index (DIGS), to go from September to December.
In the present paper, an analysis of standards in the circulars pigmentation present in juvenile and subadults was performed, and those were attributed to camouflage parameters. In adults, uniform and specific patterns of the pigmentation were attributed to secondary sexual aspects, which are not associated only to the reproductive period, through intensification in the anal and caudal fins and flanks of the body in males. The growth analysis showed animals aged between two and eleven years old. The constancy of growth k is larger in males (0.309) than in females (0.262), while the inverse was found in L¥ (males=211; females=226). Females mature at the age of 4 years old, while males at the age 6 years old, being the length growth speed inverse and kept larger for females from this age on.
The growth equation for the population was Ls = 226,5 (1 – e –0,236 (t + 0,917)). The marginal growth (Gi), indicated that females form ages annuli between Winter and Spring season, while males do in the Summer. For females, the annuli formation was attributed to the development of the gonads, while for males it was attributed to the lack of feeding during the post-reproduction period, possibly due to parental care. 2002 © - All rights reserved for Rodrigo C. P. Beheregaray. Im Sanchuri Stausee am Rio Uruguay in Südbrasilien wurden die Auswirkungen zahlreicher chemischer und physikalischer Faktoren auf die lokale Population von Serrasalmus spilopleura untersucht. Quelle: Rodrigo C. and P. Beheregaray: Biological Aspects of the Piranha Serrasalmus spilopleura (Characidae) in Uruguaiana County, west of Rio Grande do Sul, Brazil, Dissertação de Mestrado aprovada pela PUCRS em 2001 com o título: Aspectos da biologia da piranha Serrasalmus spilopleura (Characidae) no Município de Uruguaiana, oeste do Estado do Rio Grande do Sul, Brasil. Porto Alegre - RS – Brasil
Gruss, --Graf zu Pappenheim 06:46, 2. Feb. 2011 (CET)
- Wenn diese biologischen Aspekte für Dich unklar sind, dann greife sie bitte nicht auf. Schreibe nur, was Du auch verstehst - das vermeidet Mißverständnisse und Korrekturen. Gruß, Lohachata 23:38, 11. Feb. 2011 (CET)
- Und was sollen wir jetzt mit Deiner doch recht befremdlichen Aussage anfangen? Trägt sie in irgendeiner Art und Weise zur Verbesserung des Artikels bei? Wenn Du aktiv bei WP mitgestalten möchtest, dann verhalte Dich auch bitte sachbezogen. Vielen Dank, --Graf zu Pappenheim (Diskussion) 16:23, 7. Mär. 2012 (CET)