Perioculodes talboti, Hughes & Lowry, 2009

Hughes, L. E. & Lowry, J. K., 2009, Oedicerotidae *, Zootaxa 2260 (1), pp. 746-758 : 754-757

Perioculodes talboti sp. nov.

( Figs 5 , 6 )

? Perioculodes aequimanus . —K.H. Barnard, 1931: 121. — Lowry & Stoddart, 2003: 203 (catalogue).

Type material. Holotype, female (dissected), 3 slides, 4.1 mm, AM P78151, First Lagoon , One Tree Island, Queensland, Australia (~ 23°30.2’S 152°5.3’E), low tide, night, F. Talbot, 4 December 1966 (FT 106) . Paratypes: female (dissected mouthparts), AM P78152 (FT 106); 30+ unsexed, AM P78153 (FT 106); 25+ unsexed, AM P78154 (FT106) .

Additional material examined. 11 unsexed, AM P78155 (FT 107) ; 3 unsexed, AM P78156 (J& S 1.2) ; 1 unsexed, AM P78157 (J& S 1.2) ; 1 unsexed, AM P78158 (J& S 1.2) ; 1 unsexed, AM P78159 (J& S 1.2) ; 1 unsexed, AM P78160 (J& S 1.2) ; 2 unsexed, AM P78161 (J& S 1.4) ; 1 unsexed, AM P78162 (J& S 1.5) ; 11 unsexed, AM P78163 (J& S 2.2) ; 1 unsexed, AM P78164 (J&S 2.2.1) ; 2 unsexed, AM P78165 (J& S 2.3) ; 1 unsexed, AM P28488 (J&S 2.3.1) ; 1 unsexed, AM P78166 (J&S 2.3.3) ; 2 unsexed, AM P78167 (J&S 2.3.4) ; 1 unsexed, AM P78168 (J&S B 1.1) ; 5 unsexed, AM P78169 (J&S B 2.1) ; 1 unsexed, AM P78170 (J&S B 3.2) ; 1 unsexed, AM P78171 (J&S B 3.3) ; 1 unsexed, AM P78172 (J&S B 3.4) ; 3 unsexed, AM P78173 (J&S C 1.1.4) ; 1 unsexed, AM P78174 (J&S C 1.1.5) ; 1 unsexed, AM P78175 (J&S C 1.2.4) ; 3 unsexed, AM P78176 ( JDT / LIZ 18 ) ; 4 unsexed, AM P78177 ( JML 16.10.7) ; 2 unsexed, AM P78178 ( JML 16-10 - 8 ) ; 3 unsexed, AM P78179 ( JML 16-10 - 9 ) ; 1 unsexed, AM P78180 ( JML 20-10 - 2 ) ; 4 unsexed, AM P27191 ( PS 1 ) ; 3 unsexed, AM P27192 ( PS 1 ) ; 4 unsexed, AM P78181 ( QLD 35 ) ; 12 unsexed, AM P78182 ( QLD 35 ) ; 1 unsexed, AM P78183 ( QLD 54 ) ; 1 unsexed, AM P70985 ( QLD 1619 ) ; 1 unsexed, AM P70633 ( QLD 1621 ) ; 1 unsexed, AM P70629 ( QLD 1621 ) ; 1 unsexed, AM P70566 ( QLD 1624 ) (photo) ; 2 unsexed, AM P70872 ( QLD 1654 ) ; 1 unsexed, AM P71025 ( QLD 1714 ) ; 1 unsexed, AM P71137 ( QLD 1742 ) ; 1 unsexed, AM P78184 ( QLD 1900 ) ; 1 unsexed, AM P78185 ( QLD 1902 ) ; 11 unsexed, AM P78186 ( QLD 1922 ) ; 5 unsexed, AM P78187 ( QLD 1943 ) ; 10 unsexed, AM P78188 ( QLD 1948 ) ; 2 unsexed, AM P78189 ( QLD 1955 ) ; 1 unsexed, AM P78190 ( QLD 1960 ) ; 15 unsexed, AM P78191 ( QLD 1964 ) ; 20+ unsexed, AM P78192 ( QLD 1979 ) ; 13 unsexed, AM P78193 ( QLD 1999 ) ; 1 unsexed, AM P78194 ( QLD 2000 ) .

Type locality. First Lagoon , One Tree Island, Queensland, Australia (~ 23°30.2’S 152°5.3’E) .

Etymology. Named for Frank Talbot, the founder of the Lizard Island Research Station and the collector of this species.

Description. Based on holotype, female, 4.1 mm, AM P78151.

Head. Head rostrum well developed, distinctly exceeding cephalic lobe, slightly deflexed, apically subacute; eyes poorly developed, ommatidia dispersed, not coalesced, situated fully within head; lateral cephalic lobe absent. Antenna 1 long, exceeding article 5 on antenna 2; peduncular articles 1–2 shorter than peduncle of antenna 2; peduncular article 1 without tooth, subequal in length to article 2 and article 3; peduncular article 3 elongate, subequal to article 2; flagellum long, 6-articulate, exceeding antenna 2 peduncle, without callynophore, without calceoli. Antenna 2 about 1/5 body length; peduncle sparsely setose, not greatly enlarged, long curved spine absent; flagellum 5-articulate, subequal in length to peduncle, without calceoli. Mandible molar weakly developed, with 2 spine-like processes; left and right incisors with straight smooth blade; accessory setal row with 4 setae; palp elongate, article 2 straight. Maxilla 1 outer plate with 7 setal-teeth; inner plate with apical setae. Maxilla 2 inner plate without oblique setal row. Maxilliped inner plate present; palp article 2 not enlarged.

Pereon. Gnathopods 1–2 well developed; propodi similar in shape, subchelate. Gnathopod 1 subequal in size to gnathopod 2; carpal lobes strongly elongated and slender, fully guarding posterior margin of propodus extending beyond palm of propodus; propodus subrectangular (about 4 x as long as broad), posterodistal margin smooth, palm slightly acute, margin smooth. Gnathopod 2 subchelate; carpus extremely elongate, 3 x longer than broad, carpal lobes slender, less than half as broad as long, sitting along propodus margin, extending beyond tip of propodus; propodus subrectangular, about 3 x as long as broad, posterodistal margin smooth, palm slightly acute. Pereopods 3–4 carpi and propodi subequal in length; dactyli reduced, shorter than propodi, without apical setae. Pereopod 3 coxa anterior margin slightly rounded, anteroventral corner not produced, ventral margin truncate; propodus posterior margins without setae. Pereopod 4 coxa ventrally truncate, without posteroventral lobe; propodus posterior margins setose. Pereopods 5–6 similar in form; propodi posterior margins sparsely setose; dactyli shorter than propodi, slender, tapering, without ungues. Pereopod 7 basis posterodistal lobe vestigial, not reaching ischium.

Pleon. Epimeron 3 posterodistal corner rounded. Uropod 1 slightly shorter than uropod 2; rami with small robust setae; inner ramus smooth margin. Uropod 2 reaching end of uropod 3; rami subequal with small robust setae. Uropod 3 not greatly enlarged; rami subequal in length, with small robust setae. Telson entire, apically truncate, with 2 minute apical setae.

Habitat. Perioculodes talboti sp. nov. has been found swimming in the water column at night and on shallow coarse to fine sand bottoms (0.5 to 18 m) during the day.

Remarks. Perioculodes talboti sp. nov. appears to be most similar to P. pinguis Hirayama, 1987 in the carpal lobes that extend past the propodi in gnathopods 1–2 and the short dactyli of pereopods 3–4, however the rostrum of P. talboti is less deflexed and the ventral margin of coxa 1–2 is convex. Also in gnathopods 1– 2 the propodal palms are more acute in P. pinguis .

The extension of the carpal lobes beyond the propodi in gnathopods 1–2 also occurs in P. aequimanus mozambicus Ledoyer, 1973 ; P. longimanus (Bate & Westwood, 1868) , P. megapleon (Giles, 1888) and P. serra Walker, 1904 . Perioculodes talboti sp. nov. can be separated from these species by dactyli of pereopods 3–4 that are around one third the length of the propodi and the rami of uropods 1–3 that are subequal in length. Perioculodes talboti can be separated from other oedicerotids on the GBR by its long, slender subchelate gnathopods with subrectangular propodi and the long slender carpal lobes guarding the propodi.

Distribution. Australia. Queensland: Goodes and Hawkesbury Islands, Torres Strait (current study); Palfrey and Lizard Islands (current study);? Low Isles (K.H. Barnard 1931); One Tree Island (current study).

Figures

FIGURE 5. Perioculodes talboti sp. nov., holotype, female, 4.1 mm, AM P78151, First Lagoon, One Tree Island, Great Barrier Reef.

FIGURE 6. Perioculodes talboti sp. nov., holotype, female, 4.1 mm, AM P78151, First Lagoon, One Tree Island, Great Barrier Reef.