Lasiognathus

Theodore W. Pietsch & Tracey T. Sutton, 2015, A New Species of the Ceratioid Anglerfish Genus Lasiognathus Regan (Lophiiformes: Oneirodidae) from the Northern Gulf of Mexico, Copeia 103 (2), pp. 429-432 : 429-432

KEY TO FEMALES OF THE SPECIES OF LASIOGNATHUS

1a. Escal hooks borne on a short, transverse, fanshaped, distal appendage (Bertelsen and Pietsch, 1996:404, fig. 2) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Lasiognathus beebei Regan and Trewavas, 1932

1b. Escal hooks borne on an elongate, cylindrical, distal appendage _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2

2a. Escal bulb with a membranous anterior crest; prolongation of distal appendage absent ( Bertelsen and Pietsch, 1996:404, fig. 3) _ _ _ _ _ _ _ _ _ Lasiognathus waltoni Nolan and Rosenblatt, 1975

2b. Escal bulb without a membranous anterior crest; prolongation of distal appendage present _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3

3a. A cylindrical, internally pigmented, anterior escal appendage arising from base of escal bulb; distal escal appendage with a pair of slender, filamentous prolongations ( Figs. 2 , 3 ) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Lasiognathus dinema Pietsch and Sutton , new species

3b. Cylindrical, internally pigmented, anterior escal appendage absent; distal escal appendage with a single cylindrical or compressed prolongation _ _ _ _ _ _ 4

4a. Distal escal appendage with a short, cylindrical prolongation (length 5.2–8.6% SL) emerging ante- riorly from bases of escal hooks, without lateral serrations or filaments; posterior escal appendage cylindrical ( Bertelsen and Pietsch, 1996:405, fig. 4) _ _ _ _ _ _ _ _ _ Lasiognathus intermedius Bertelsen and Pietsch, 1996

4b. Distal escal appendage with an elongate, com- pressed prolongation (length 2.9–20.8% SL) emerg- ing anteriorly from bases of escal hooks, bearing lateral serrations and/or tiny filaments on distal tip; posterior escal appendage broad, laterally compressed _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 5

5a. Three darkly pigmented escal hooks; length of distal escal appendage 8.0–12.5% SL (in specimens ranging from 30–77 mm); length of prolongation of distal escal appendage increasing with standard length from 7.7% SL (in 30 mm specimen), to 10.8% SL (55.5 mm), to 20.8% SL (77 mm); prolongation of distal escal appendage bearing numerous lateral serrations and distal filaments ( Bertelsen and Pietsch, 1996:407, fig. 5) _ _ _ _ _ _ _ _ _ _ _ _ Lasiognathus saccostoma Regan, 1925

5b. Two lightly pigmented escal hooks; length of distal escal appendage 3.8% SL (in a 157 mm specimen); length of prolongation of distal escal appendage 2.9% SL (in 157 mm holotype); prolongation of distal escal appendage without lateral serrations, but bearing a series of six tiny distal filaments ( Pietsch, 2005:78, figs. 1, 2) _ _ _ _ _ _ _ _ _ _ _ _ Lasiognathus amphirhamphus Pietsch, 2005

Figures

Fig. 2. Escae of Lasiognathus dinema Pietsch and Sutton, new species, in preservation: (A) Holotype, UW 152603, female, 95 mm SL, left lateral view; (B) Paratype, UW 152604, female, 30 mm SL, right lateral view (prolongation of distal escal appendage rotated to show anterior face).

Fig. 3. Esca of Lasiognathus dinema Pietsch and Sutton, new species, paratype, UW 154626, female, 36 mm SL, left lateral view, in preservation. Image courtesy of L. Malarky (NSUOC).