Robert H. Gore

Studies on decapod crustacea from theIndian River Region of Florida: XI. Community composition, structure, biomass andspecies-areal relationships of seagrass and drift algae-associated macrocrustaceans

A 1-year study, using six 10 m2 drop nets at monthly stations, was conducted on the seagrass and drift algae-associated macrocrustaceans (primarily Decapoda) in the Indian River lagoon on the central eastern Florida coast. The macrocrustacean community consisted of 38 species, in 28 genera and 17 families, the majority of which were caridean (grass) shrimp and brachyuran crabs. Two caridean shrimp, a pagurid crab, and a penaeid shrimp were numerically dominant species which, together with 10 less numerous species, were considered to be characteristic representatives of the macrocrustacean community. Both a species-area and individuals-area relationship were demonstrated using a combinatorial statistical method, and a modification of the Fisher species-individuals relationship. The community as a whole responded in numbers of individuals, and in total crustacean biomass, to increases in seagrass and drift algae (as plant biomass g−1 m−2). Macrocrustacean community diversity appeared to be regulated by above-ground plant abundance, and is thus a function of habitat complexity. The consistency of decapod species composition indicated that the community is both predictable and resilient, with resultant stability due, in some measure, to habitat diversity produced by the periodic trimonthly increases in drift algae abundances. Competitive exclusion may be more important than predation on this seagrass bed in regulating the within-habitat diversity of the macrocrustacean community.

Studies on the provenzanoi and other pagurid groups: VI. Larval and early juvenile stages of Pagurus ochotensis Brandt (Decapoda; Anomura; Paguridae) from a northeastern Pacific population, reared under laboratory conditions

Zoeal, megalopal, and early juvenile stages of Pagurus ochotensis (Brandt, 1851) from a northeastern Pacific population are described from laboratory-reared individuals. Zoeal and megalopal development in this population is compared with that described for a population of this species from Hokkaido, Japan. First and second juvenile crab stages of this species are described for the first time. The nearly identical developmental morphology of the two populations supports the earlier synonymy of the northeastern Pacific species, Pagurus alaskensis (Benedict) with P. ochotensis.

Microphrys Bicornutus (Latreille, 1825) : The Complete Larval Development Under Laboratory Conditions with Notes on Other Mithracine Larvae (Decapoda: Brachyura: Majidae)

ABSTRACT The complete larval development, consisting of two zoeal stages and a megalopa, and the first crab stage is described for the shallow-water western Atlantic spider crab Microphrys bicornutus. Data from laboratory cultures indicate that the species can complete its planktonic development in less than a week, and is able to attain first crab stage in as few as 10 days. The zoeal stages of M. bicornutus show a great many similarities to known zoeae in other genera within the subfamily Mithracinae, including species of the American genus Mithrax, and to Mucrocoeloma, and to a lesser extent the Indo-West Pacific genera Tiarinia and Micippa. Morphological features shared among both the zoeal and megalopal stages of the various mithracine genera are compared, and phylogenetic relationships within Microphrys, Mithrax, and Macrocoeloma are proposed.

Re-establishment of the Family Eumedonidae Dana, 1853 (Crustacea: Brachyura)

ZDRAVKO STEVCIC Rudjer Boskovic Institute, 52210 Rovinj, Yugoslavia PETER CASTRO Biological Sciences Department, California State Polytechnic University, Pomona, California 91768-4032, U.S.A. ROBERT H. GORE 288-2 Winner Circle, Naples, Florida 33942, U.S.A. (Accepted30 October 1987) On the basis of a re-examination of all available data concerning the systematic position and status of the genu Eumedonuss and allied genera it is concluded that these taxa form a separate family within the superfamily Xanthoidea (sensu Guinot, 1978). The family is characterized not only by particular morphological features but by the symbiotic mode of life of its members.

Echinoecus pentagonus (A. Milne Edwards, 1879): larval development and systematic position (Crustacea: Brachyura: Xanthoidea nec Parthenopoidea)

ABSTRACT The complete larval development of Echinoecus pentagonus (A. Milne Edwards), a brachyuran crab symbiotic with echinoderms, is described and illustrated. Development consists of three (or occasionally four) zoeal stages, each lasting from 4-8 days, and a megalopal stage lasting from 11-27 days ( = 13.8 days). Morphological and developmental characters exhibited by the larvae of E. pentagonus indicate that the species is not a member of the family Parthenopidae, as previously thought, but instead shows strong morphological relationships to xanthid crabs, subfamily Pilumninae. Only further studies on larvae of species in the subfamily Eumedoninae will determine whether E. pentagonus and other eumedonine genera presently assigned to the Parthenopidae will eventually be reassigned either as a separate family (Eumedonidae), or as a subfamily (Eumedoninae) of the Xanthidae sensu lato or the Pilumnidae sensu Guinot.

Neopisosoma Angustifrons (Benedict, 1901 ) : the Complete Larval Development Under Laboratory Conditions, With Notes On Larvae of the Related Genus Pachycheles (Decapoda Anomura, Porcellanidae ) 1)

[Larven von Neopisosoma angustifrons, einem tropischen Porcellaniden-Krebs, wurden unter Laboratoriumsbedingungen bei Zimmertemperatur (22°-24° C) aufgezogen. Die Larvalentwicklung wird beschrieben und die Stadien werden abgebildet. Wie bei den meisten anderen Porcellanidenlarven, gibt es drei Stadien: Zoea I, Zoea II, und Megalopa-Stadium. Die Larven von Neopisosoma werden mit den Larval- und Postlarval-Stadien der eng verwandten Gattung Pachycheles verglichen. Fur die beiden Gattungen werden Larvenmerkmale von potentieller taxonomischer Bedeutung diskutiert., Larven von Neopisosoma angustifrons, einem tropischen Porcellaniden-Krebs, wurden unter Laboratoriumsbedingungen bei Zimmertemperatur (22°-24° C) aufgezogen. Die Larvalentwicklung wird beschrieben und die Stadien werden abgebildet. Wie bei den meisten anderen Porcellanidenlarven, gibt es drei Stadien: Zoea I, Zoea II, und Megalopa-Stadium. Die Larven von Neopisosoma werden mit den Larval- und Postlarval-Stadien der eng verwandten Gattung Pachycheles verglichen. Fur die beiden Gattungen werden Larvenmerkmale von potentieller taxonomischer Bedeutung diskutiert.]

Studies on the Provenzanoi and Other Pagurid Groups: II. A Reexamination of the Larval Stages of Pagurus hirsutiusculus hirsutiusculus (Dana) (Decapoda: Anomura: Paguridae) Reared in the Laboratory

ABSTRACT In a continuing study of the usefulness of larval characters in determining phylogenetic relationships among species of the hermit crab genus Pagurus, the developmental sequence of Pagurus hirsutiusculus hirsutiusculus (Dana) has been reexamined using laboratory-reared larvae. Results of the current study have shown that several significant characters were either overlooked or misinterpreted in earlier studies.

Studies on the Provenzanoi and Other Pagurid Groups: V. The Larval Stages of Pagurus Arenisaxatilis Harvey and Mclaughlin, 1991 (Decapoda: Anomura: Paguridae), Reared in the Laboratory

ABSTRACT The larvae of a second newly described species of the provenzanoi group of pagurid hermit crabs from the eastern Pacific have been reared in the laboratory from hatching through late juvenile stages. The 4 zoeal stages and 1 megalopal stage are described and illustrated. The larval characters of this species are compared with Pagurus vetaultae Harvey and McLaughlin, the first of the Pacific species of the group to be reared. Both species appear more closely related to some of the 5 Atlantic species than to one another.

STUDIES ON DECAPOD CRUSTACEA FROM THE INDIAN RIVER REGION OF FLORIDA. XXIII. THE LABORATORY CULTURED ZOEAL STAGES OF THE CORAL GALL-FORMING CRAB TROGLOCARCINUS CORALLICOLA VERRILL, 1908 (BRACHYURA: HAPALOCARCINIDAE) AND ITS FAMILIAL POSITION

The first 5 zoeal stages of the brachyuran, coral-inhabiting, gall-forming crab Troglocarcinus corallicola Verrill, 1908, are described and illustrated. Based on the sequential appearance of morphological characters, this species passes through at least 5, and perhaps 6 or 7 larval stages before metamorphosing to megalopa. The zoeae can be easily recognized in the plankton by a combination of lateral aliform expansions on the fourth, and a distinct dorsal caplike process on the second abdominal somite. The number of abdominal somites (5) remains constant throughout the first 5 (and probably subsequent) zoeal stages. Evidence from larval morphology supports the contention based on adult characters, that the Hapalocarcinidae are closely related to the Pinnotheridae, as well as having close affinities to the Hymenosomatidae and Leucosiidae. The family Hapalocarcinidae is a widespread group of approximately 27 species in at least 8 genera (Fize and Serene, 1957; Takeda and Tamura, 1979). The major distribution is throughout the Pacific and Indian Oceans, with only 3 species presently recorded from the Atlantic Ocean (2 from the western Atlantic and one from the eastern Atlantic). The family is unique in that the members symbiotically associate with scleractinian corals by forming galls, dens, or depressions within the substratum of the living corallum. Previous studies have been primarily taxonomic in nature, but the group is so taxonomically confusing that its phylogenetic position within the brachyuran Decapoda has not been established with certainty. Within the family, first zoeal larvae have been briefly described and inadequately illustrated for only 3 species (Potts, 1915; Edmondson, 1933; Fize, 1956; Al-Kholy, 1963; as reviewed in Castro, 1976), so that the larval development within the family can be considered practically unknown. Of the 2 species known from the western Atlantic Ocean, Troglocarcinus corallicola is the most widespread, being recorded from Bermuda (the type-locality of Verrill, 1908), Straits of Florida, northeastern Gulf of Mexico, and Dominica, British West Indies (Rathbun, 1937; Shaw and Hopkins, 1977). The species is a known symbiont of madreporarian hermatypic corals, in which it forms lunate galls or dens. However, our collections made off the central eastern Florida coast showed the species to be an associate of the Ivory Tree Coral Oculina varicosa Lesueur, 1820, as well. Among specimens obtained were several ovigerous females. These offered an opportunity to study the larval development of the species, and perhaps clarify systematic relationships within the family. Accordingly, this paper reports on the first 5 larval stages of Troglocarcinus corallicola, and (as far as previously published data allow) compares morphological characters of the zoeae with those noted for the Pacific species Hapalocarcinus marsupialis Stimpson, 1859 (Potts, 1915; Al-Kholy, 1963) and Cryptochirus minutus Edmondson, 1933 [=C. coralliodytes Heller, 1861, fide Utinomi, 1944].

Studies On Decapod Crustacea From the Indian River Region of Florida. Iii. Callinectes Bocourti a. Milne Edwards, 1879 (Decapoda, Portunidae) From the Central East Coast of Florida

Callinectes bocourti, a large, swimming crab of some commercial importance, is found predominantly throughout the West Indies and down to Brazil. Holt huis (1959) noted that the species was the most abundant portunid found in Surinam, probably because it was able to tolerate lower salinities than other swimming crabs in the region. Provenzano (1961) recorded the species for the first time in the continental United States based on a mature male specimen deposited in the University of Miami Marine Laboratory Museum; the specimen was collected at Matheson Hammock, Biscayne Bay, Florida. Recently, Perry (1973) reported a second specimen, from Biloxi Bay, Mississippi, thus extending the known range of the species to the northern Gulf of Mexico. We report here yet a third specimen, a mature male, which was collected in the Indian River, Indian River County, Vero Beach, Florida, during the summer of 1973 by Mr. Gerald Herting then with the Florida State Department of Natural Resources. The Indian River record is approximately 150 miles (250 km) north on the central eastern coast of Florida from the specimen-locality reported by Proven zano, though not as far north latitudinally as Perrys record. Our specimen, as Provenzanos and Perrys material, also agrees well with the description provided by Rathbun (1930: 128) although we noted several apparently minor differ ences. In her diagnosis, Rathbun noted the lateral spine as less than twice as long as the preceding tooth. In our specimen, the posterolateral spine was 10.9 mm long, whereas the penultimate lateral tooth was 5.0 mm long. Strict adherence to Rathbuns key would place the species as Callinectes toxotes Ordway, 1863, an eastern Pacific species and the possible analog of C. bocourti. However, all other features, including intramedial ratios, frontal teeth, and male gonopods were in agreement with that indicated by Rathbun in her description for C. bocourti. Neither Provenzano nor Perry gave color notes for their respective specimens. The coloration in our specimen, only recently preserved, was noteworthy. Holt huis (1959: 203) stated that the color pattern for this species was remarkable, the palm of the chela being dark reddish brown above and whitish below, the