J. Parasitol., 99(2), 2013, pp. 318–326 Ó American Society of Parasitologists 2013 A NEW SPECIES OF TRICHOSOMOIDIDAE (NEMATODA) FROM SKIN OF RED SNAPPER, LUTJANUS CAMPECHANUS (PERCIFORMES: LUTJANIDAE), ON THE TEXAS–LOUISIANA SHELF, NORTHERN GULF OF MEXICO Carlos F. Ruiz, Candis L. Ray, Melissa Cook*, Mark A. Grace*, and Stephen A. Bullard Aquatic Parasitology Laboratory, Department of Fisheries and Allied Aquacultures, College of Agriculture, Auburn University, 203 Swingle Hall, Auburn, Alabama 36849. Correspondence should be sent to: [email protected] ABSTRACT: Eggs and larvae of Huffmanela oleumimica n. sp. infect red snapper, Lutjanus campechanus (Poey, 1860), were collected from the Texas–Louisiana Shelf (28816036.5800 N, 93803051.0800 W) and are herein described using light and scanning electron microscopy. Eggs in skin comprised fields (1–5 3 1–12 mm; 250 eggs/mm2) of variously oriented eggs deposited in dense patches or in scribble-like tracks. Eggs had clear (larvae indistinct, principally vitelline material), amber (developing larvae present) or brown (fully developed larvae present; little, or no, vitelline material) shells and measured 46–54 lm(x¼50; SD 6 1.6; n¼213) long, 23–33 (27 6 1.4; 213) wide, 2–3 (3 6 0.5; 213) in eggshell thickness, 18–25 (21 6 1.1; 213) in vitelline mass width, and 36–42 (39 6 1.1; 213) in vitelline mass length with protruding polar plugs 5–9 (7 6 0.6; 213) long and 5–8 (6 6 0.5; 213) wide. Fully developed larvae were 160–201 (176 6 7.9) long and 7–8 (7 6 0.5) wide, had transverse cuticular ridges, and were emerging from some eggs within and beneath epidermis. The new species differs from its congeners by having eggs ,65 lm in total length and that have a brown eggshell when fully developed, an envelope throughout development, and irregularly-dispersed eggshell spines plus a larva .110 lm long with transverse cuticular ridges. The eggs lack a spindle-shaped envelope, polar filaments, and eggshell ridges. This is the first report of a species of Huffmanela from a snapper (Lutjanidae) or from the Gulf of Mexico. A table of egg and larval characteristics, hosts, and localities for Huffmanela spp. is provided. Species of Huffmanela Moravec, 1987 comprise intracellular Louisiana Shelf (28816036.5800 N, 93803051.0800 W, approximately 200 km (Moravec et al., 1998) and intercellular (Moravec, 1987) nematodes off Galveston Bay, Texas), northern Gulf of Mexico, aboard the F/V Simple Man. Upon sighting the infected areas of skin, its head, i.e., that customarily are defined by the morphology of their eggs and syncranium without gill arches (Fig. 1), was frozen and later (4 November larvae (Table I), with only 5 of 17 (29%) accepted species having 2011) delivered to Auburn University where it was subsequently (23 descriptions that include details of the adult male or female January 2012) thawed in 10% neutral buffered formalin for several days (Huffman and Moravec, 1988; Moravec et al., 2005; Carballo and before parasitological examination. The thawed, formalin-fixed head was Navone, 2007; Justine, 2007). Adults and eggs infect extra-intestinal then carefully bisected along the supraoccipital plane, i.e., cleaved in half sites such as gill and skin epithelia, skeletal muscle, serosa and using a reciprocating saw, allowing for a clearer view of the luminal surfaces of the buccal cavity. The preopercle, metapterygoid, symplectic, mesentery, swim bladder, and bone (Moravec, 1987, 2001; Moravec and quadrate then were excised as a single unit with associated soft tissues and Campbell, 1991; Moravec and Garibaldi, 2000; Moravec and using a scalpel, allowing for a clearer view of the skin surface covering the Justine, 2010). Adults are seldom collected and difficult to extract urohyal and branchiostegals. These tissue surfaces were examined with a from host tissue due to their small size and delicate nature, but also stereomicroscope for the presence of eggs, larval nematodes, and adult perhaps because the females die and deteriorate soon after nematodes. Foci of infected and non-infected skin were excised using depositing eggs (Moravec et al., 1998; Zˇd’a´rska´et al., 2001). It scissors, scalpel, and hemostats and then photographed with the aid of a stereomicroscope or were wet-mounted on coverslipped glass slides has been stated that few characters exist to discriminate eggs; (without coverslip pressure) and photographed using a compound light however, numerous diagnostic features have been developed and microscope (LM) equipped with differential interference contrast (DIC) employed to differentiate these species based on egg morphology optical components (Bullard et al., 2012). All nematode eggs and larvae (Table I). Developmental stages of these eggs also contain were measured with an ocular micrometer while viewed using a 3100 oil important taxonomic information and expand our knowledge of immersion objective and DIC. Composite illustrations of those eggs and their life cycles and general biology (Moravec, 1987; Huffman and larvae were aided with a drawing tube and supplemented by digital photomicrographs. Skin patches containing eggs and eggs rinsed by gentle Moravec, 1988; Moravec et al., 1998; Moravec and Fajer-Avila, pipetting for scanning electron microscopy (SEM) were routinely 2000; Moravec and Garibaldi, 2000, 2003; Justine, 2004, 2005, processed by dehydration through a graded ethanol series, desiccated in 2007, 2011; Carballo and Navone, 2007; Bullard et al., 2012). hexamethyldisilazane for 1–3 hr followed by evaporation, and mounted on In October 2011, a red snapper, Lutjanus campechanus (Poey, metal stubs using 2-sided sticky tape. Morphometrics are reported in 1860), (Perciformes: Lutjanidae), with noticeable skin markings micrometers (lm) as a range followed by the mean 6 standard deviation (SD) and sample size (n) in parentheses. was observed and collected from the Gulf of Mexico off Texas. Anatomical terms for the fish skull follow Gregory (1933). Fish Herein we describe the markings, identify the etiological agent, nomenclature follows Eschmeyer (2012). The Gulf of Mexico is defined as describe a new species of Huffmanela Moravec, 1987, and thereby per Felder et al. (2009): its boundaries span westward from Cabo Catoche, also provide the first record of a species of Huffmanela from a Quintana Roo, Mexico (21833000.0000 N, 87800000.0000 W) following a line snapper (Lutjanidae) or from the Gulf of Mexico. extending northeast from Cabo Catoche to Cabo de San Antonio, Cuba (21851000.0000 N, 84857000.0000 W), further extending along the northern coast of Cuba to Punta Hicacos, Cuba (23812000.0000 N, 81808000.0000 W) MATERIALS AND METHODS and west of a line extending from Punta Hicacos to Key Largo, Florida (25806000.0000 N, 80826000.0000 W). The infected red snapper (male, 604 mm total length, 3.1 kg) was captured by a bottom long-line set on 15 October 2011 on the Texas– DESCRIPTION Received 24 June 2012; revised 6 September 2012; accepted 14 Huffmanela oleumimica n. sp. Ruiz and Bullard September 2012. (Figs. 2–31) * Southeast Fisheries Science Center, National Oceanic and Atmo- Diagnosis (based on light microscopy of 213 eggs plus sputter-coated, spheric Administration, 3209 Frederic Street, Pascagoula, Mississippi infected skin, eggs, and larvae): Fields of eggs 1–5 3 1–12 mm, with 39567. irregularly-shaped margins, comprising approximately 250 eggs per mm2, DOI: 10.1645/GE-3249.1 amber or brown in color (eggs with clear shells not visible grossly, see 318 TABLE I. Eggs, larvae, hosts, sites, and localities for Huffmanela spp. (ordered by egg size). Egg Polar Plug Shell Shell Shell Envelope Larva Species L 3 W* plug W surface layers thick type L 3 W Host family Site Locality References† Huffmanela branchialis 45–52 3 23–30 p — smooth — 2–3 smooth 150 3 7 Nemipteridae gill SW Pacific Justine (2004) Huffmanela oleumimica 46–54 3 23–33 p 5–8 spinous ol, id 2–3 smooth 160–201 3 7–8 Lutjanidae skin GoM present study Huffmanela paronai 48–51 3 21–24 p 6–7 smooth od, il 3 smooth — Xiphiidae skin Med Moravec and Garibaldi (2000) Huffmanela filamentosa 48–53 3 25–30 p — smooth — 3 absent 150 3 7 Lethrinidae gill SW Pacific Justine (2004) Huffmanela canadensis 48–63 3 24–27 p 6 ridged od, il 2–3 absent — Scorpaenidae skin NE Pacific Moravec et al. (2005) Huffmanela moraveci 50–57 3 23–31 p 8–10 spinous od, il 3–5 smooth 108 3 — Atherinopsidae skin, gill SW Atlantic Carballo and Navone (2007) Huffmanela japonica 58–69 3 26–30 p 6–9 protuberances od, il 4–5 smooth — 3 9 Mulidae me NW Pacific Moravec et al. (1998) Huffmanela longa 58–72 3 23–32 pf — smooth — 2–4 absent 140–168 3 4–5 Lethrinidae sb, me SW Pacific Justine (2007) Huffmanela huffmani 54–60 3 30–33 p 6–7 smooth od, il 5–6 spinous — 3 6 Centrarchidae sb Texas, USA Moravec (1987); Huffman and Moravec (1988) Huffmanela mexicana 63–69 3 30–33 p 6 smooth od, il 4–5 smooth, exposed — 3 6 Tetraodontidae sb NE Pacific Moravec and Fajer-Avila plugs (2000) Huffmanela balista 63–78 3 32–41 p — ridged — 5–6 smooth 245–295 3 6–8 Balistidae sb SW Pacific Justine (2007) RUIZ ET AL.— Huffmanela plectropomi 64–82 3 29–50 p 6 — — 3–4 absent — Serranidae m SW Pacific Justine (2011) Huffmanela schouteni 69–75 3 27–33 p 6–9 smooth od, il 3–5 protuberances 210 3 4–6 Exocoetidae sb, me Med, W Moravec and Garibaldi Atlantic (2003); Moravec and Campbell (1991); HUFFMANELA OLEUMIMICA Schouten et al. (1968) Huffmanela ossicola 73–88 3 35–40 p — smooth — 8–10 smooth 250 3 — Labridae gill, bone SW Pacific Justine (2004) Huffmanela carcharhini 75–110 3 42–63 np 8–13 smooth ol, id 5–10 absent 188–273 3 7–13 Carcharhinidae skin NW Atlantic MacCallum (1925; 1926); NC Pacific Moravec (1987); Bullard et al.