Abstract: Onychophoran worms seldom attack spiders because spiders are agile and dangerous prey. Here we report an onychophoran feeding on a spider (possibly a Ctenidae) in Sierra Llorona, Colón, Panamá (9, 35863°-79,70287°; altitude 491 m).
Key words: Neotropical invertebratesNeotropical invertebrates,adhesive netadhesive net,private reserveprivate reserve,tropical rainforesttropical rainforest.
Resumen: Los gusanos de terciopelo rara vez atacan a las arañas porque éstas son presas ágiles y peligrosas. Aquí informamos de un onicóforo comiendo una araña (posiblemente de la familia Ctenidae) en Sierra Llorona, Colón, Panamá (9,35863°-79,70287°; 491 msnm).
Palabras clave: invertebrados neotropicales, red adhesiva, reserva privada, selva tropical.
Note
A velvet worm (Onychophora: Peripatidae) feeding on a free ranging spider in Sierra Llorona, Panama
Gusano de terciopelo (Onychophora: Peripatidae) alimentándose de una araña en Sierra Llorona, Panamá
Universidad Estatal a Distancia de Costa Rica
Received: 15 November 2017
Revised document received: 12 December 2017
Accepted: 30 January 2018
Onychophoran worms are ancient predators that can only live in moist microhabitats and hunt for small invertebrates at night (mostly insects, myriapods, spiders and crustaceans, Read & Hughes, 1987; Monge-Nájera, Barrientos & Aguilar, 1993). However, many spiders are agile and dangerous to onychophorans, and probably they are not frequent prey (Read & Hughes, 1987; Dias & Lo-Man-Hung, 2009); furthermore, some spiders can kill and eat onychophorans (Franco & Monge-Nájera, 2016). Here we report an onychophoran feeding on a spider in Panama.
The observation was made on July 18, 2017, at 10:21 pm, in Sierra Llorona Private Reserve, Colón, Panama; 9,35863°-79,70287°; 491 masl; Premontane Very Moist Forest; precipitation: 3000 a 3500 mm (Autoridad Nacional del Ambiente de Panamá, 2010).
On a mossy rock at the edge of a creek, the first author found an onychophoran feeding on a spider, which was still moving its legs slowly ( Figure 1). That same night he saw four more onychophorans in understory vegetation, but none were feeding. The worm was about 7 cm long and the spider about 4cm long. For future reference, we propose the common name of "Sierra Llorona Leather-Brown Collared Onychophoran" for this species (Sosa-Bartuano, Monge-Nájera & Morera-Brenes, 2018).
The spider seemed to be a ctenid; the family Ctenidae has at least 16 species in Panama (Quintero, 2005). They do not build webs and include aggressive and poisonous species that hunt at night among soil vegetation. These are dangerous spiders and perhaps the onychophoran found a weakened individual and secured it with adhesive, but it is also possible that the worm killed a healthy spider thanks to its stealth hunting behavior (Morera-Brenes & Monge-Nájera, 2010).
We thank Diomedes Quintero and William Eberhard for information on the behavior and possible identity of the spider.
EDITED BY CAROLINA SEAS
Fig 1.
Onychophoran found feeding on a spider in Sierra Llorona, Colón, Panamá (July, 2017). Photographs by Jesse Ashcroft and M. González.
Fig 1.
Onychophoran found feeding on a spider in Sierra Llorona, Colón, Panamá (July, 2017). Photographs by Jesse Ashcroft and M. González.
