Monday, December 11, 2023

[Crustacea • 2023] Cerapus rivulus • A New Species of Cerapus (Amphipoda: Senticaudata: Ischyroceridae) from Mae Klong Estuary, Gulf of Thailand, with A Discussion on their nesting and types of mating behaviour


Cerapus rivulus 
Katnoum, Saetung Keetapithchayakul, Rahim & Wongkamhaeng, 2023
  

 Abstract
The first representative of the genus Cerapus in the Gulf of Thailand, Cerapus rivulus sp. nov., is described from specimens sampled from Mae Klong Estuary, the inner Gulf of Thailand. The main identifying characteristics of this new amphipod species are pereonites 1 and 2 without constriction; male gnathopod propodus palm transverse with long posterior defining tooth and well-developed anterodistal recurved tooth adjacent to propodus articulation; pereopod 6 coxa without fine fringe setae ventrally, basis with setae on posterior margin; and telson with deep cleft. An updated identification key for the 25 known species in the genus is also presented. A discussion on their nesting and types of mating behaviour is provided.

Key Words: Amphawa, Cerapus, mating behaviour, nesting behaviour
  
Cerapus rivulus sp. nov., holotype, male (THNHM -19377).
A. Habitus of the male holotype; B. Antenna 1; C. Antenna 2; D. Gnathopod 1; E. Palm of gnathopod 1; F. Gnathopod 2; G. Palm of gnathopod 2. Scale bars: 0.2 mm.

Cerapus rivulus sp. nov.
 A. Holotype male lateral (THNHM -19377); B. A specimen in its tube with protruding head and antennae; C. Paratype female front (THNHM-19379).


Chanikan Katnoum, Tosaphol Saetung Keetapithchayakul, Azman Abdul Rahim and Koraon Wongkamhaeng. 2023. A New Species of Cerapus (Amphipoda, Senticaudata, Ischyroceridae) from Mae Klong Estuary, with A Discussion on their nesting and types of mating behaviour. Zoosystematics and Evolution. 99(2): 557-574. DOI: 10.3897/zse.99.107974