Pygidianops

Pygidianops
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Siluriformes
Family:	Trichomycteridae
Subfamily:	Glanapteryginae
Genus:	Pygidianops; Myers, 1944
Type species
	Pygidianops eigenmanni; Myers, 1944

Pygidianops is a genus of pencil catfishes native to South America.

Species

There are currently four recognized species in this genus:[1]

Pygidianops amphioxus de Pinna & Kirovsky, 2011
Pygidianops cuao Schaefer, Provenzano, de Pinna & Baskin, 2005
Pygidianops eigenmanni Myers, 1944
Pygidianops magoi Schaefer, Provenzano, de Pinna & Baskin, 2005

Distribution

P. eigenmanni is from the Rio Negro basin in Brazil.[2] P. cuao is known only from Cuao River drainage basin. P. magoi is known only from lower Orinoco mainstem between Ciudad Bolívar and Barrancas in Venezuela.[3]

Description

Species of Pygidianops share the extreme reduction of pigmentation, loss of the dorsal fin, the loss or extreme reduction of pectoral fins, a reduced lateral line, and the reduction or complete loss of eyes in some species. These fish are markedly miniaturized, yet retain a relatively well-ossified skeleton comparable in both bone differentiation and degree of calcification to that observed in larger trichomycterids.[3]

P. cuao is distinguished from congeners by the presence of diminutive eyes (vs. eyes absent in both other species), posterior naris absent (vs. nares bilaterally paired), and the presence of a triangular skin flap at mouth corner (vs. skin flap absent).[3] P. magoi is distinguished from all congeners by the absence of pectoral and anal fins (vs. fins present), posterior naris absent (vs. present, nares bilaterally paired), four laterosensory pores on the head (vs. six), and by the presence of 9–10 caudal fin rays (vs. 12–13). With all of its fins lost except the caudal fin, P. magoi represents the most extreme fin loss among ostariophysans.[3] P. eigenmanni lacks eyes but has its anal and pectoral fins.[3]

gollark: \@everyone

gollark: Go(lang) = bad.

gollark: ``` [...] MIPS is short for Millions of Instructions Per Second. It is a measure for the computation speed of a processor. Like most such measures, it is more often abused than used properly (it is very difficult to justly compare MIPS for different kinds of computers). BogoMips are Linus's own invention. The linux kernel version 0.99.11 (dated 11 July 1993) needed a timing loop (the time is too short and/or needs to be too exact for a non-busy-loop method of waiting), which must be calibrated to the processor speed of the machine. Hence, the kernel measures at boot time how fast a certain kind of busy loop runs on a computer. "Bogo" comes from "bogus", i.e, something which is a fake. Hence, the BogoMips value gives some indication of the processor speed, but it is way too unscientific to be called anything but BogoMips. The reasons (there are two) it is printed during boot-up is that a) it is slightly useful for debugging and for checking that the computer[’]s caches and turbo button work, and b) Linus loves to chuckle when he sees confused people on the news. [...]```I was wondering what BogoMIPS was, and wikipedia had this.

gollark: ```Architecture: x86_64CPU op-mode(s): 32-bit, 64-bitByte Order: Little EndianCPU(s): 8On-line CPU(s) list: 0-7Thread(s) per core: 2Core(s) per socket: 4Socket(s): 1NUMA node(s): 1Vendor ID: GenuineIntelCPU family: 6Model: 42Model name: Intel(R) Xeon(R) CPU E31240 @ 3.30GHzStepping: 7CPU MHz: 1610.407CPU max MHz: 3700.0000CPU min MHz: 1600.0000BogoMIPS: 6587.46Virtualization: VT-xL1d cache: 32KL1i cache: 32KL2 cache: 256KL3 cache: 8192KNUMA node0 CPU(s): 0-7Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx lahf_lm pti tpr_shadow vnmi flexpriority ept vpid xsaveopt dtherm ida arat pln pts```

gollark: I think it's a server thing.

References

Froese, Rainer and Pauly, Daniel, eds. (2012). Species of Pygidianops in FishBase. February 2012 version.
Ferraris, Carl J. Jr. (2007). "Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types" (PDF). Zootaxa. 1418: 1–628.
Schaefer, Scott A.; Provenzano, Francisco; de Pinna, Mario; Baskin, Jonathan N. (November 29, 2005). "New and Noteworthy Venezuelan Glanapterygine Catfishes (Siluriformes, Trichomycteridae), with Discussion of Their Biogeography and Psammophily" (PDF). American Museum Novitates (3496): 1–27.

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[1] Froese, Rainer and Pauly, Daniel, eds. (2012). Species of Pygidianops in FishBase. February 2012 version.

[Ferraris-2] Ferraris, Carl J. Jr. (2007). "Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types" (PDF). Zootaxa. 1418: 1–628.

[Schaefer-3] Schaefer, Scott A.; Provenzano, Francisco; de Pinna, Mario; Baskin, Jonathan N. (November 29, 2005). "New and Noteworthy Venezuelan Glanapterygine Catfishes (Siluriformes, Trichomycteridae), with Discussion of Their Biogeography and Psammophily" (PDF). American Museum Novitates (3496): 1–27.