Pterygoplichthys reproduction in Mexico

[Silurus]

Jasso, RAR, AC Mendoza, FA Sánchez, ED Pardo & CAM Palacios, 2013. The biological and reproductive parameters of the invasive armored catfish Pterygoplichthys disjunctivus from Adolfo López Mateos El Infiernillo Reservoir, Michoacán-Guerrero, Mexico. Revista Mexicana de Biodiversidad 84: 318–326.

Abstract

Invasive Pterygoplichthys disjunctivus (Weber, 1991) (synonymy: Liposarcus multiradiatus) armored catfish were first reported in Mexico in 1995 and have spread successfully in several aquatic ecosystems. In Adolfo López Mateos El Infiernillo Reservoir, Michoacán – Guerrero, the population of this armored catfish is growing substantially because natural predators are not present and exploitation by humans does not occur. Over a complete annual cycle, we studied the following population parameters: weight, total and standard length, the relationship of weight to total length, the hepatosomatic (HSI) and gonadosomatic (GSI) indices, total fecundity (TF) and relative fecundity (RF). The average total (TL) and standard lengths (SL) were 248 ± 37.5 and 188 ± 30.7 mm, respectively, and the average weight (W) was 135.3± 66.8 g. The largest fish reported was 520 mm in TL and weighed 1 280 g. The species showed an extended reproductive season from May to November, as indicated by the GSI, TF and RF. The strongest reproductive peak occurred from July through October. During the annual cycle, the highest monthly average fecundity was 2 447 eggs, and the average relative fecundity was 12.6 eggs per g of fish (August and September). This information will be crucial for calculating the current biomass and future growth of the population. The calculation of these results could provide a basis for the exploitation of this resource for human consumption and animal feeds.

[DKcincy]

Also apparently has been caught/found in the wild in USA too.
http://nas2.er.usgs.gov/viewer/omap.aspx?SpeciesID=767

[MatsP]

Also apparently has been caught/found in the wild in USA too.
http://nas2.er.usgs.gov/viewer/omap.aspx?SpeciesID=767

Yes, and about everywhere else in the world that isn't freezing too often. Florida, Texas (probably in the states between too, just not something I remember reading about), Hawaii, India, Vietnam, Singapore, Malaysia, Indonesia, Thailand, Bangladesh - I'm sure I've missed some out on that list. I'm pretty sure they are in Africa too. I read a record of them being in Poland too, but whether they survive a harsh winter is more debatable.

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Mats

[magdalo]

The local government of Marikina City, in the Philippines, is offering monetary reward for every kilo of this L-Cat caught (dead or alive). It is considered a pest as it is destroying the ecological balance of a local river in that municipality.

[Birger]

A past thread on these invasions http://www.planetcatfish.com/forum/view ... 14&t=24602

Birger

[Jools]

The calculation of these results could provide a basis for the exploitation of this resource for human consumption and animal feeds.

Wonder if they'd make a nice ceviche?

Jools

[racoll]

The calculation of these results could provide a basis for the exploitation of this resource for human consumption and animal feeds.

The local government of Marikina City, in the Philippines, is offering monetary reward for every kilo of this L-Cat caught (dead or alive). It is considered a pest as it is destroying the ecological balance of a local river in that municipality.

Very frequently, the idea of commercialising invasive species is proposed. It sounds like a logical solution, but can people making money from these species really be trusted? Will they not, when picking get slim, introduce them to new or more convenient sites? Surely if they have a financial incentive to catch these creatures, why would they want them to run out?

[Jools]

True, but an "invasive species of the month" might work?

Jools