Palaemon mundusnovus De Grave & Ashelby, 2013

Herrera-Barquín, Hiram, Leija-Tristán, Antonio & Favela-Lara, Susana, 2018, Updated checklist of estuarine caridean shrimps (Decapoda: Caridea) from the southern region of Laguna Madre, Tamaulipas, Mexico, with new records and a key for taxonomic identification, Check List 14 (2), pp. 479-494 : 482

Palaemon mundusnovus De Grave & Ashelby, 2013

Figure 3A, B Material examined (150 specimens). Among seagrass. 8 March 2014 (UANL-FCB-C17-8119), S1 (24°29.1000ʹ N, 097°41.4500ʹ W), 49 specimens (5♀, 44♂); 8 March 2014 (UANL-FCB-C17-8123), S2 (24°29.1833ʹ N, 097°41.9667ʹ W), 1 specimen (♂); 9 March 2014 (UANL- FCB-C17-8130), S3 (24°29.2667ʹ N, 097°45.9833ʹ W), 14 specimens (5♀, 9♂); 4 August 2014 (UANL-FCB- C17-8133), S1 (same point), 86 specimens (30♀, 57♂); 18 February 2017 (UANL-FCB-C17-8162), S3 (same point), 43 specimens (29♀, 14♂).

Distribution. Vineyard Sound, Massachusetts, to Port Aransas, Texas ( Holthuis 1952); Laguna de Mecoacán, Tabasco; Laguna de Términos, Campeche; Bahía de la Ascensión, Quintana Roo; Isla Arenas, Yucatán, México ( Chace 1972, Williams 1984, Román-Contreras 1988, Domínguez et al. 2003, Barba-Macías et al. 2005, Wick- sten 2005a, Barba-Macías 2012).

Previous records from Laguna Madre. Hildebrand (1958), Barba-Macías (1999), Leija-Tristán et al. (2000), Rodríguez-Almaraz et al. (2000), Sheridan and Minello (2003, Laguna Madre of Texas), Barba-Macías et al. (2005), Barba-Macías (2012).

Remarks. The rostrum bears 4 or 5 ventral teeth, seldom 3; our material typically showed 4 ventral teeth, ranging from 3 to 5 ( Fig. 3A), and agreed with descriptions given by Abele and Kim (1986), and also Holthuis (1952), particularly in the number of ventral teeth of rostrum, the dorsal teeth behind the margin of orbit, and also the presence of a blunt and tiny tooth on the dactylus of second pereopod. This species is reported as Palaemonetes intermedius in all the literature, but following the transfer of P. intermedius (Holthuis, 1949) to the genus Palaemon , the name became the junior homonym of Palaemon intermedius Stimpson, 1860 . Thus, De Grave and Ashelby (2013) proposed the replacement name now in use. All members of the genus Palaemonetes were transferred to Palaemon by these authors based on morphological, cladistic and genetic evidence ( Pereira 1997, Ashelby et al. 2012, De Grave and Ashelby 2013), concluding that the presence/absence of mandibular palp can no longer be used as the sole character that separates both genera. Furthermore, larval development studies comparing 3 coastal Palaemonetes species with 3 species of Palaemon concluded that the differences within the genera are more pronounced that between genera, which suggests a close evolutionary relationship ( Knowlton and Vargo 2004).