Discovery of South American suckermouth armored catfishes (Loricariidae, Pterygoplichthys spp.) in the Santa Fe River drainage, Suwannee River basin, USA

Abstract

In 2007, the invasive ctenophore Mnemiopsis leidyi was observed for the first time in Limfjorden (Denmark) where it exhibited mass occurrence in late summer while the indigenous and usually dominating common jellyfish, Aurelia aurita, was nearly absent. Both species were further studied in 2008 and 2009 and it was found that the additional predation pressure by M. leidyi caused the zooplankton stocks to be severely depressed. Here, we report on the population dynamics and predation impact of M. leidyi and A. aurita in Limfjorden in 2010 and 2011. In 2010, M. leidyi was observed in Limfjorden for the first time in August with the highest density and largest size in the central parts (Skive Fjord). The estimated half-life of zooplankton (copepods) was only important in Skive Fjord in mid August 2010 when the jointpredation impact of A. aurita and M. leidyi was 2.3 d. In 2011, no M. leidyi were observed on the first cruise (3 August), while during the second cruise (17 November) it was observed in large numbers. The western most location (Venø Bugt) was dominated by large sized (≤ 60 mm) M. leidyi, while the average size decreased towards the central parts of the fjord-system. The proportion of cydippid larvae increased from west to the central parts thus suggesting rapid reproduction and population-size expansion. The bio-volumes of ctenophores were highest in the central part with 85 ml m -3 in Løgstør Bredning, which may be compared to the greatest mean bio-volume of about 184 ml m -3 observed in the Black Sea in 1989 when the zooplankton and fish stocks collapsed. Analysis of available hydrographic data and model calculations indicates that re-invasion of M. leidyi from the North Sea seeded the autumn population in Limfjorden in mid-September.

Invasion of South American suckermouth armoured catfishes Pterygoplichthys spp. (Loricariidae) in Kerala, India - a case study

“…The species delineation within the genus Pterygoplichthys remains in chaos primarily because the four closely related species such as P. anisitsi, P. multiradiatus, P. pardalis and P. disjunctivus are separated only based on the nature of their abdominal patterns (Nico et al 2012). All the specimens collected during the study lacked an elevated supraoccipital process and have the supraoccipital bone bordered posteriorly by three scutes.…”

“…Wu et al (2011) also hypothesized possible hybrid origin of the introduced Pterygoplichthys exhibiting "hybrid superiority" which might have increased their fitness during invasions. According to Nico et al (2012) some of the introduced populations of Pterygoplichthys show such extensive variations among individuals that they might best be described as "hybrid swarms".…”

“…The ability to withstand water pollution (Welcomme & Vidthayanom 2003), toleration of poor oxygen content in water by means of accessory respiration with diverticula of the gastrointestinal tract (Armbruster 1998), lower number of predators and less vulnerability to predation due to spiny fins and hard external 'armour' (Zworykin and Budaev 2013), occasional migrations across land and low current velocity (Nico et al 2012), peculiarities in reproduction and development such as prolonged reproductive period, batch spawning, development of eggs at very low water levels and active parental care (Hoover et al 2004;Liang et al 2005), coupled with greater feeding opportunities in smaller streams (Nico et al 2012) help them to invade a variety of ecosystems and to establish successfully. A survey conducted among the ornamental fish traders and hobbyists in Thiruvananthapuram City revealed an interesting fact: when the specimens grow in size, the traders and hobbyists find it difficult to keep them in tanks and therefore release them into the natural drainages (Bijukumar, unpublished information).…”

“…Pterygoplichthys is one of the fast dispersing species in the invaded countries, introduced primarily through uncontrolled pet trade and their invasion results in serious ecological and economic consequences (Nico et al 2012). This paper documents the invasion of Pterygoplichthys spp.…”

Population Structure and Body Size of the Suwannee Alligator Snapping Turtle (Macrochelys suwanniensis) in Northern Florida

“…-The SFR originates in swamps near Lake Santa Fe and Lake Alto in northern Florida and is classified as a blackwater stream (Florida Natural Areas Inventory 2010), but it is a heterogeneous system that becomes increasingly spring-fed as it flows along its , 115-km westward course to the Suwannee River ( Fig. 1; Scott et al 2004;Nico et al 2012). Approximately 60 km downstream from its origin (elevation 5 42 m), the upper SFR disappears underground into a swallet known as the SFR Sink.…”