Laetmatophilus hala J. L. Barnard 1970

Laetmatophilus hala

DIAGNOSIS OF FEMALES AND JUVENILES.—Head with 3 dorsal cusps in transverse row, anteroventral corner with small cusp; pereonite 1 with 2 axial dorsomedial cusps and 2 lateral cusps on each side, pereonites 2, 3, 4, 5, 7 with 1 dorsal and 1 lateral cusp on each side, pereonite 6 with 1 dorsal cusp and 1 very weak ridge on lateral surface, pereonites 5–7 coalesced; lateral margins of pereonites 1–7 with small ridge-cusp above coxae; pleonites 1–2 each with dorsal cusp and pleonite 1 with small dorsolateral ridge on each side; young specimens with lateral supracoxal ridges and dorsolateral teeth absent, middorsal cusps represented by humps, anteroventral cephalic cusp absent; only coxae 3–4 in adult female with ventral points; article 2 of gnathopod 2 with sharp anterodistal cusp, article 4 with medium-sized posterodistal process; gnathopod 1 palm longer than posterior margin of article 6 and lined with long setae, defined by sharp, slender, short, feathered spine, dactyl slightly longer than palm and distally multifid, lobe of article 5 evenly bulging; outer ramus of uropod 1 half as long as inner.

DESCRIPTION.—Pereopods 2–7 and antennae 1–2 missing from all material except pereopods 3–4 of juvenile in JLB Hawaii 3, generally like those of L. tuberculatus Bruzelius (Sars, 1895, pl. 226); mouthparts also like drat species but inner plate of maxilla 1 obsolescent, right mandibular molar with large flake and seta, left molar with small flake and no seta; epistome strongly conical; uropod 3 a small flap with medial setule. Specimen of JLB Hawaii 5 lacks lateral cusps on pleonite 1, and the adult of JLB Hawaii 3 has all cusps less produced than on the holotype, and pereonite 1 and pleonite 1 have no lateral cusps.

HOLOTYPE.—Bishop Museum collections, catalog number 7298, female, 1.8 mm.

TYPE-LOCALITY.—JLB Hawaii 6, off Barbers Point, Hawaii, 30 m, coralline footballs, 29 January 1967.

MATERIALS.—JLB Hawaii 3 (2), 5 (1), 6 (1).

RELATIONSHIP.—This species probably has its closest relationships with L. hystrix (Haswell, 1880b), but that species has at least one more dorsolateral cusp on each side of pereonites 1–7 and pleonite 1 has 2 dorsal medials, the anteroventral cephalic cusp is larger and coxae 5–6 have ventral cusps. Considerable developmental change occurs in L. hala, and perhaps terminal adults develop the characters of L. hystrix.

Laetmatophilus armatus (Norman) (Sars, 1895, pl. 227, fig. 1) has fewer dorsal cusps than L. hala, the former having primarily a double dorsal spiniform set along the midline of pereonites 2–7 and pleonites 1–2 and lacking an anteroventral cephalic cusp.

Laetmatophilus leptocheir K. H. Barnard (1937) has the outer ramus of uropod 1 about two-thirds as long as the inner, the head and pereonite 1 lack dorsal cusps or keels and the hand of gnathopod 1 is very slender.

DISTRIBUTION.—Hawaiian Islands.

Podocerus Leach

Identifications of the tropical species in this genus have been subject to confusion after 1906 when Stebbing adequately summarized the known species which at that time had limited distributions. Since then, two species, Brazilian P. brasiliensis (Dana) and New Zealandian P. cristatus (Thomson), have been reported from localities far from tropical waters and P. brasiliensis has come to be considered circumtropical.

One of those records identified by J. L. Barnard (1962a, fig. 30) from open-sea southern California is undoubtedly erroneous as his figure shows a head entirely different from that seen in P. brasiliensis from Hawaii and vaguely seen in Dana’s (1853) drawings of the original establishment of the species. The ocular lobes of P. brasiliensis fill the anteroventral corner of the head, whereas in the Californian material they occur behind a sharp corner. The record by J. L. Barnard (1959) from Newport Bay has the correct head although the dactyl of gnathopod 1 is apically multispinose as in the open-sea populations and thus differs from the dactyl in tropical individuals. The Californian open-sea material should be accorded a name different from P. brasiliensis but estuarine-lagoonal populations in California may represent a form of P. brasiliensis imported by human agencies.

Gnathopod 1 of male P. brasiliensis from Hawaii (J. L. Barnard, 1955a) and Ceylon (Walker, 1904, as P. synaptochir) has a distal hemispherical lobe on a truncate article 5, whereas Dana’s (1855) and J. L. Barnard’s (1959) materials have the lobe on article 5 stretching the breadth of the article.