Branchinectidae

Diagnosis. Male. Second antennae bisegmented, clearly separate from each other. Basal antennomere often bearing diverse medial structures near its base: a rough pad with setae and or spinulae, a smooth tubercle, a wide spine, a welt with a hanging protuberance or other outgrowths. Besides, it may be smooth or variously ornamented with rows of spiny or blunt spines and / or smooth or spiny crests, or diverse isolate processes. Distal antennomere usually unbranched, and often with a rasp-like area with mesetiform elements along the distal posterior edge up to its tip. Frontal and antennal appendages lacking. Gonopods free and widely separated at their base, extending ventrolaterally; basal rigid portion (non-eversible) partially visible in dorsal view; apical portion eversible, bearing two dentate warts. Vas deferens straight or looped. Rigid basal portion of gonopods bearing a medial projection with one or two processes. Female. Second antennae unsegmented, ending in a distal point; medially, it can bear additional structures ranging from a small medial bulge with spinulae or setae to a strong conical medial projection. Often with dorsal, dorsolateral and / or lateral rows of variously shaped projections or tubercles, in a variable number of thoracic segments including the genital ones. Brood pouch elongate, cylindrical or fusiform, extending beyond genital segments. Both sexes. Mandibles with no sexual dimorphism; molar surface in both mandibles asymmetrical, with one row of well-developed teeth on the dorsal margin of the left mandible and multibranched projections on the dorsal margin of the right mandible except for the few predatory species, in which mandibles are symmetrical, both carrying strong teeth at the dorsal edges. Maxillae showing no sexual dimorphism. Maxilla 1 with a ventral short spine and numerous long setae (18 – 25). Maxilla 2 well developed, with its distal portion flattened and expanded, bearing 5 – 30 apical setae pointing medially, and 2 – 5 setae anteriorly directed, with setulae all around, near the middle of the anterior edge of the appendage. Eleven pairs of thoracopods with or without sexual dimorphism in the shape and setose armature of endopodites; each thoracopod bearing one pre-epipodite. Two genera: Branchinecta and Archaebranchinecta.