Micah D. Bakenhaster

LIFE HISTORY OF GLOSSOBIUS HEMIRAMPHI (ISOPODA: CYMOTHOIDAE): DEVELOPMENT, REPRODUCTION, AND SYMBIOSIS WITH ITS HOST HEMIRAMPHUS BRASILIENSIS (PISCES: HEMIRAMPHIDAE)

Abstract This research examines the life cycle of the parasitic cymothoid isopod Glossobius hemiramphi and its role as a symbiont with its fish host, ballyhoo (Hemiramphus brasiliensis). Samples of H. brasiliensis were collected from July 1997 to October 1998 in nearshore waters of south Florida. Fish were randomly culled from a commercial lampara net fishery, and independent of the fishery, fish were collected with cast nets or hook and line. The average parasite prevalence was 10.1%, observed in 2,928 fish collected year round. Monthly prevalence ranged from 4.6 to 18.2% and was highest in the summer on small young-of-the-year fish. Prevalence declined with fish size from a high of 38.0% for fish 11-16 cm to a low of 3.3% for fish 28-29 cm. Ovigerous females were observed throughout the year and no within-brood mortality was evident. Marsupiumites developed through five distinct ontogenetic stages, and the final marsupial stage (manca) was likely immediately infestive upon release. Diminutive males (2.8-12.4 mm) were attached to the hosts gill arches, and larger females (16.9-35.6 mm) occupied the buccal cavity. Only a single fish older than age-1 was infested. These results indicate that Glossobius hemiramphi is a protandric hermaphrodite with an annual life cycle. There was no evidence of a parasitic effect on the host fish condition (weight-length), but we cannot exclude the possibility that infested fish have a higher mortality rate than uninfested fish, at least temporarily (∼1 year).

Philometra floridensis sp. n. (Nematoda: Philometridae) from the ovary of red drum Sciaenops ocellatus (Osteichthyes: Sciaenidae) off the coast of Florida, USA.

A new nematode species, Philometra floridensis sp. n. (Philometridae), is described from male and female specimens found in the ovary of red drum, Sciaenops ocellatus (Linnaeus) (Sciaenidae, Perciformes), from the Gulf of Mexico off Treasure Island, Florida, USA. Based on light and scanning electron microscopy examination, the new species differs from most other gonad-infecting Philometra spp. in having a smooth gubernaculum with a distinct dorsal tooth on the distal tip. The new species is most similar to P. carolinensis Moravec, de Buron & Roumillat, 2006, but differs in length and shape of spicules. It can be distinguished from P. carolinensis and other species with unknown males, by the markedly greater body length of gravid females (up to about 100 cm). Philometra floridensis is the third valid gonad-infecting species of Philometra reported from sciaenids.

Cardicola laruei Short, 1953 (Digenea: Aporocotylidae) from Heart of Seatrout, Cynoscion spp., (Perciformes: Sciaenidae) in the Gulf of Mexico and Atlantic Ocean: Taxonomic Redescription, First Observations of Egg and Miracidium, and Comments on Geographic Distribution and Host Specificity

Abstract The heart and gill of 125 spotted seatrout, Cynoscion nebulosus (Cuvier, 1830), (Perciformes: Sciaenidae) from 5 Gulf of Mexico localities (Mississippi Sound [n  =  18] [30°23′21″N; 88°51′44″W], Apalachicola Bay [n  =  17] [29°40′18″N; 85°00′09″W], Suwannee Sound and Wacasassa Bay [n  =  22] [29°7′55″N; 83°2′24″W], Tampa Bay [n  =  58] [27°41′58″N; 82°37′49″W], and Charlotte Harbor [n  =  10] [26°43′07″N; 82°11′27″W]); 40 spotted seatrout from 2 northwestern Atlantic Ocean localities (St. Johns River Estuary [n  =  28] [30°22′29″N; 81°34′08″W] and Indian River Lagoon [n  =  12] [28°5′31″N; 80°36′08″W]); and 103 sand seatrout, Cynoscion arenarius Ginsburg, 1930, from 2 Gulf of Mexico localities (Mississippi Sound [n  =  102] and Tampa Bay [n  =  1]) were examined for the presence of fish blood flukes (Digenea: Aporocotylidae). One adult aporocotylid was collected from the heart of each infected spotted seatrout captured in Tampa Bay (6 of 58 infected, 10%) and St. Johns River Estuary (1 of 28 infected, 4%) as well as from the heart of the single sand seatrout from Tampa Bay. We identified these aporocotylids as Cardicola laruei Short, 1953, based on light and scanning electron microscopy that matched them to the original species description of C. laruei, the type specimens in the United States National Parasite Collection (holotype USNPC 37377; paratypes USNPC 37378–9), and other of Shorts original specimens now in our own collection. The present study is the first reported collection of this aporocotylid (i) from Tampa Bay, (ii) from the Atlantic Ocean, (iii) from the heart of spotted seatrout, and (iv) since its original description in 1953. Among other significant morphological features previously not ascribed to C. laruei, these specimens have a spheroid anterior sucker with concentric rows of minute spines anterior to the mouth. The fully developed, spindle-shaped egg of C. laruei embeds in the gill epithelium of its fish host proximal to the afferent branchial arterioles and encloses a ciliated miracidium. This report significantly contributes to our knowledge of C. laruei by (i) extending its known geographic distribution to a new ocean basin (Atlantic Ocean), (ii) adding supplemental morphological data derived from light and scanning electron microscopy, (iii) providing the first published observations of nonadult life history stages (egg and miracidium), and (iv) confirming that sympatric, congeneric seatrouts are infected by C. laruei.

New philometrids (Nematoda, Philometridae) from head tissues of two serranid fishes (Epinephelus morio and Mycteroperca microlepis) off Florida, northern Gulf of Mexico

A new species of nematode, Philometra morii sp. nov. (Philometridae), is described from males and gravid females collected from the mouth cavity of the red grouper, Epinephelus morio (Valenciennes) (Serranidae, Perciformes), from the northen Gulf of Mexico, off Florida, USA. The new species is characterized mainly by the length of spicules (84–90 and 72–87 μm) and the length (54 μm) and structure of the gubernaculum in the male, and by the presence of three large oesophageal teeth protruding from the mouth, the number and arrangement of small cephalic papillae (8 papillae in 4 pairs of external circle and 6 single papillae of internal circle), the length (1.09–1.50 mm) and structure of the oesophagus and two large papilla-like caudal projections, and by the length of their bodies (19.34–30.07 mm). Philometra morii is the third species of this genus reported from E. morio in the Gulf of Mexico, differing from the two previously described species, in addition to morphological features, by the site of infection in this host (mouth cavity and sinuses vs oculo-orbits or gonads). From the same region (northern Gulf of Mexico, off Florida), gravid females of Philometra Costa, 1845, morphologically and biometrically similar to those of P. morii, were found in the subcutaneous tissues and sinuses of the head of another serranid fish (gag), Mycteroperca microlepis (Good et Bean). Although their conspecificity with P. morii cannot be excluded, they have been designated as Philometra sp. until conspecific males are discovered and described. Based on light and scanning electron microscopy examination (latter used only for females), both these forms are described.

A New Species of Philometra (Nematoda: Philometridae) From the Sand Perch Diplectrum formosum (Serranidae) Off Florida, Northern Gulf of Mexico

Abstract A new nematode species, Philometra diplectri n. sp. (Philometridae), is described from male and female specimens found in unidentified tissues of head and anterior trunk (males) and subcutaneously in the mouth and under the operculum (females) of sand perch, Diplectrum formosum (Linnaeus) (Serranidae, Perciformes), from the northern Gulf of Mexico off Florida (Florida Middle Grounds). Based on light and scanning electron microscopy examination, the new species differs from other congeners parasitizing the subcutaneous tissues, fins, tissues of the buccal cavity, and gill covers or gill arches of marine and brackish-water fishes, mainly in having 8 conspicuously large cephalic papillae of the external circle, the absence of caudal projections, and the shape and small size of the anterior inflation of the esophagus in gravid females, and in possessing 5 pairs of caudal papillae and spicules 66–78 µm long in males. Philometra diplectri is the first known species of this genus whose gravid females are parasitic in the head tissues of serranid fishes.

Pseudorhabdosynochus species (Monogenoidea, Diplectanidae) parasitizing groupers (Serranidae, Epinephelinae, Epinephelini) in the western Atlantic Ocean and adjacent waters, with descriptions of 13 new species

Seventeen of twenty-three species of groupers collected from the western Atlantic Ocean and adjacent waters were infected with 19 identified species (13 new) of Pseudorhabdosynochus Yamaguti, 1958 (Dactylogyridea, Diplectanidae); specimens of the Spanish flag Gonioplectrus hispanus, coney Cephalopholis fulva, marbled grouper Dermatolepis inermis, mutton hamlet Alphestes afer, and misty grouper Hyporthodus mystacinus were not infected; the yellowmouth grouper Mycteroperca interstitialis and yellowfin grouper Mycteroperca venenosa were infected with unidentified species of Pseudorhabdosynochus; the Atlantic creolefish Paranthias furcifer was infected with an unidentified species of Diplectanidae that could not be accommodated in Pseudorhabdosynochus. The following species of Pseudorhabdosynochus are described or redescribed based entirely or in part on new collections: Pseudorhabdosynochus americanus (Price, 1937) Kritsky & Beverley-Burton, 1986 from Atlantic goliath grouper Epinephelus itajara; Pseudorhabdosynochus yucatanensis Vidal-Martínez, Aguirre-Macedo & Mendoza-Franco, 1997 and Pseudorhabdosynochus justinella n. sp. from red grouper Epinephelus morio; Pseudorhabdosynochus kritskyi Dyer, Williams & Bunkley-Williams, 1995 from gag Mycteroperca microlepis; Pseudorhabdosynochus capurroi Vidal-Martínez & Mendoza-Franco, 1998 from black grouper Mycteroperca bonaci; Pseudorhabdosynochus hyphessometochus n. sp. from Mycteroperca interstitialis; Pseudorhabdosynochus sulamericanus Santos, Buchmann & Gibson, 2000 from snowy grouper Hyporthodus niveatus and Warsaw grouper Hyporthodus nigritus (new host record); Pseudorhabdosynochus firmicoleatus n. sp. from yellowedge grouper Hyporthodus flavolimbatus and snowy grouper H. niveatus; Pseudorhabdosynochus mcmichaeli n. sp., Pseudorhabdosynochus contubernalis n. sp., and Pseudorhabdosynochus vascellum n. sp. from scamp Mycteroperca phenax; Pseudorhabdosynochus meganmarieae n. sp. from graysby Cephalopholis cruentata; Pseudorhabdosynochus beverleyburtonae (Oliver, 1984) Kritsky & Beverley-Burton, 1986 from dusky grouper Mycteroperca marginata; Pseudorhabdosynochus mizellei n. sp. from red hind Epinephelus guttatus; Pseudorhabdosynochus williamsi n. sp. from rock hind Epinephelus adscensionis; Pseudorhabdosynochus bunkleywilliamsae n. sp. from Nassau grouper Epinephelus striatus; Pseudorhabdosynochus mycteropercae n. sp. from tiger grouper Mycteroperca tigris; and Pseudorhabdosynochus tumeovagina n. sp. from speckled hind Epinephelus drummondhayi. Pseudorhabdosynochus woodi n. sp. from red hind Epinephelus guttatus is described based on specimens from the US National Parasite Collection (USNPC). Drawings of the haptoral and copulatory sclerites of the type specimens in the USNPC of Pseudorhabdosynochus monaensis Dyer, Williams & Bunkley-Williams, 1994 from rock hind Epinephelus adscensionis are presented. Finally, a note confirming Pseudorhabdosynochus epinepheli Yamaguti, 1958 rather than its senior synonym Pseudorhabdosynochus epinepheli (Yamaguti, 1938) Kritsky & Beverley-Burton, 1986 as the type species of Pseudorhabdosynochus is provided.

Monogenoidean parasites of the gill lamellae of the sheepshead Archosargus probatocephalus (Walbaum) (Perciformes: Sparidae) from the Indian River Lagoon, Florida, with descriptions of four new species of Euryhaliotrema Kritsky & Boeger, 2002 (Dactylogyridae)

Examination of the gill lamellae of three sheepshead Archosargus probatocephalus (Walbaum) from the Indian River Lagoon in Florida revealed six species of Monogenoidea: Microcotyle archosargi MacCallum, 1913 (Microcotylidae); Neobenedenia sp. (Capsalidae); and four new species of Euryhaliotrema Kritsky & Boeger, 2002 (Dactylogyridae). The prevalence of all helminths was 100%, except for Neobenedenia sp., which was represented by a single immature specimen. The four new species, Euryhaliotrema carbuncularium n. sp., E. dunlapae n. sp., E. amydrum n. sp. and E. spirulum n. sp., are described and with E. carbunculus (Hargis, 1955) Kritsky & Boeger, 2002 apparently constitute a monophyletic clade of Euryhaliotrema spp. that parasitise sparid hosts in the western hemisphere. The Indian River Lagoon in Florida represents a new locality record for M. archosargi, and the sheepshead is apparently a new host record for a member (Neobenedenia sp.) of the Capsalidae.

Pseudorhabdosynochus sulamericanus (Monogenea, Diplectanidae), a parasite of deep-sea groupers (Serranidae) occurs transatlantically on three congeneric hosts (Hyporthodus spp.), one from the Mediterranean Sea and two from the western Atlantic

Little is known of the diversity of the monogenean parasites infesting deep-sea groupers, and there is even less information available about their geographic distributions within the ranges of their hosts. To improve our understanding of these host-parasite relationships we conducted parasitological evaluations of the deep-water Haifa grouper Hyporthodus haifensis from the southern Mediterranean off Tunisia and Libya. We collected more than one species of diplectanid monogeneans from this host, but among these only one dominant species was abundant. This proved to be morphologically very similar to Pseudorhabdosynochus sulamericanus Santos, Buchmann & Gibson, 2000, a species originally described from the congeneric host H. niveatus off Brazil and also recorded from H. niveatus and H. nigritus off Florida. Here, we conducted a morphological comparison between newly collected specimens and those previously deposited in museum collections by other authors. Further, we used COI barcoding to ascertain the specific identity of the three host species to better elucidate the circumstances that might explain the unexpectedly broad distribution of P. sulamericanus. We assigned our specimens from H. haifensis to P. sulamericanus primarily on the basis of morphological characteristics of the sclerotized vagina. We also noted morphological characteristics of eastern and western Atlantic specimens that are not clearly described or not given in previous descriptions and so prepared a redescription of the species. We confirmed, by COI barcoding, that no sister-species relationships were evident among the three hosts of P. sulamericanus. Our observation that P. sulamericanus infects unrelated host species with putatively allopatric distributions was unexpected given the very limited dispersive capabilities and the high degree of host specificity common to members of Pseudorhabdosynochus. This transatlantic distribution raises questions with regard to phylogeography and assumptions about the allopatry of Atlantic grouper species from the Americas and Afro-Eurasia. Here, we propose some hypothetical explanations for our findings.

A New Gonad-Infecting Species of Philometra (Nematoda: Philometridae) from the Atlantic Spanish Mackerel Scomberomorus maculatus (Scombridae) off the Atlantic Coast of Florida and South Carolina

Abstract: A new nematode species, Philometra atlantica n. sp. (Philometridae), is described from male and female specimens found in the ovary of the Atlantic Spanish mackerel, Scomberomorus maculatus (Mitchill) (Scombridae, Perciformes), off the Atlantic coast of Florida and South Carolina. Based on light and scanning electron microscopy examination, the new species differs from most other gonad-infecting Philometra spp. in the length of spicules (111–126 μm), number and arrangement of genital papillae, and a U-shaped, dorsally interrupted caudal mound in the male. A unique feature among all gonad-infecting philometrids is the presence of 2 reflexed dorsal barbs on the distal end of the gubernaculum. From a few congeneric, gonad-infecting species with unknown males, it can be distinguished by some morphological and biometrical features found in gravid females (body length, length of first-stage larvae or esophagus, structure of caudal end) and by the host type (fish family) and geographical distribution. Philometra atlantica is the fourth valid gonad-infecting species of Philometra reported from fishes of the family Scombridae.

Rhabdosynochus spp. (Monogenoidea: Diplectanidae) infecting the gill lamellae of snooks, Centropomus spp. (Perciformes: Centropomidae), in Florida, and redescription of the type species, R. rhabdosynochus.

Abstract Examination of the gill lamellae of 3 species of Centropomus spp. (Centropomidae) from 9 localities around the southern coast of Florida revealed 3 species of Rhabdosynochus (Monogenoidea, Diplectanidae). The common snook, Centropomus undecimalis, was infected with Rhabdosynochus rhabdosynochus (30 of 37 infected; prevalence 81%), Rhabdosynochus hargisi (9 of 37; 24%), and Rhabdosynochus hudsoni (20 of 37; 46%); the fat snook, Centropomus parallelus, with R. rhabdosynochus (12 of 22; 55%) and R. hudsoni (8 of 22; 36%) (new host records for both); and the tarpon snook, Centropomus pectinatus, with R. hudsoni (3 of 4; 75%) (new host record). Snooks infected with R. rhabdosynochus were collected only from tidal waters of salinity ≤10.4 ppt, where the parasite dominated the monogenoidean community. Rhabdosynochus hargisi and R. hudsoni showed greater salinity tolerance; the former dominated where salinity was ≥28.8 ppt. Thus, salinity appears to be a determinate factor in partitioning the monogenoidean community, while water depth and temperature and host population (as defined by collection locality) did not appear to affect occurrence of Rhabdosynochus spp. on snooks in Florida. With the exception of Tampa Bay for R. hargisi, each locality represented a new geographic record for the respective diplectanid. The type species, R. rhabdosynochus, is redescribed based on specimens collected from its type host, C. undecimalis.