Rheumatobates

Bergroth, 1892

water strider

Rheumatobates is a of (: ) containing approximately 30–39 described . Males of this genus exhibit elaborate secondary sexual traits, including highly modified and hind legs used during pre-copulatory struggles with females. These sexually antagonistic traits have evolved through multiple independent origins and show an escalation pattern across the genus . The genus occupies diverse aquatic including estuarine environments and mangroves.

Rheumatobates palosi by (c) Matthew Pintar, some rights reserved (CC BY), uploaded by Matthew Pintar. Used under a CC-BY license.

Rheumatobates trulliger by (c) Matthew Pintar, some rights reserved (CC BY), uploaded by Matthew Pintar. Used under a CC-BY license.

Rheumatobates by (c) Matthew Pintar, some rights reserved (CC BY), uploaded by Matthew Pintar. Used under a CC-BY license.

Pronunciation

How to pronounce Rheumatobates: /ˌrjuːmətoʊˈbeɪtiːz/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Males are distinguished from other by bizarre modifications of the and hind legs, including structures used to grasp females around the and lift their hind legs above the water surface during pre-copulatory struggles. -level identification relies on male , antennae, and fore leg characteristics.

Images

Habitat

Estuarine waters and mangroves; occupies water surface .

Distribution

Colombian Caribbean region; Colombia; Vermont, United States.

Diet

Feeds on terrestrial ; lipid composition indicates synthesis of 20:5 from C-18 precursors.

Behavior

Males repeatedly harass females, which respond by evasive skating. If grasped, a pre-copulatory struggle ensues; short struggles typically lead to copulation, while prolonged struggles result in disengagement. During pre-copulatory struggles, males use modified to encircle the female's and hind legs to lift the female's hind legs off the water surface. Neither antennae nor hind legs are used during copulation itself. Females isolated from males for extended periods become less reluctant to mate. After brief copulation, males withdraw their and dismount.

Similar Taxa

GerrisFreshwater with different lipid composition (lower triglyceride , different profiles) and lacking the elaborate male secondary sexual modifications of and hind legs seen in Rheumatobates.
HalobatesMarine distinguished by presence of 22:6 derived from marine plankton food, higher triglyceride lipid (74–92% vs. 46–72%), and lack of the elaborate sexually antagonistic male appendage modifications characteristic of Rheumatobates.