Crustaceans from a tropical estuarine sand-mud flat, Pacific, Costa Rica, (1984-1988) revisited

Abstract

Abstract:The availability of data sets for time periods of more than a year is scarce for tropical environments. Advances in hardware and software speed-up the re-analysis of old data sets and facilitates the description of population oscillations. Using recent taxonomic literature and software we have updated and re-analized the information on crustacean diversity and population fluctuations from a set of cores collected at a mud-sand flat in the mid upper Gulf of Nicoya estuary, Pacific coast of Costa Rica (1984)(1985)(1986)(1987)(1988). A total of 112 morphological species of macroinvertebrates was found, of which 29 were crustaceans. Taxonomic problems, maily with the peracarids, prevented the identification of a group of species. The abundance patterns of the crab Pinnixa valerii, the ostracod Cyprideis pacifica, and the cumacean Coricuma nicoyensis were analized with the Generalized Additive Models of the free software R. The models evidenced a variety of population oscillations during the sampling period. These oscillations probably included perturbations induced by external factors, like the strong red tide events of 1985. In additon, early on 1984 the populations might have been at an altered state due to the inpact of El Niño 1982-83. Thus, the oscillations observed during the study period departed from the expected seasonality (dry vs rainy) pattern and are thus considered atypical for this tropical estuarine tidal-flat. Crustacean diversity and population peaks were within the range of examples found in worldwide literature. However, abundances of the cumacean C. nicoyensis, an endemic species, are the highest reported for a tropical estuary. Comparative data from tropical tidal flat crustaceans continues to be scarce. Crustaceans (total vs groups) had population changes in response to the deployment of predator exclusion cages during the dry and rainy seasons of 1985. Temporal and spatial patchiness characterized the abundances of P. valeri, C. pacifica and C. nicoyenis.

Integrative Taxonomic Study of the Purse Crab Genus Persephona Leach, 1817 (Brachyura: Leucosiidae): Combining Morphology and Molecular Data

“…In his re-examination of the holotype of Persephona subovata (Rathbun, 1894), Hendrickx [ 19 ] noted its strong similarity to Iliacantha hancocki Rathbun, 1935, with these differing only in the size of peripheral carapace granules and the relative distance between posterior teeth. While he did not synonymize these species he noted they should at very least not be assigned to different genera, though the matter thus far has remained unresolved [ 3 , 20 , 21 ].…”

A new species ofMegalobrachiumStimpson, 1858 (Crustacea: Anomura: Porcellanidae) from the eastern Pacific coasts of Panama and Colombia, with re-description ofM. erosum

“…40, figure 2; 1962, p. 191; Haig et al , 1970, pp. 26, 29; Hendricks, 1993a, p. 7, b, p. 310, list 11; Hendricks & Harvey, 1999, p. 378; Boschi, 2000, p. 93; Vargas & Cortés, 2004, p. 467, Table 1; Hendricks et al , 2005, p. 175; García-Madrigal & Andréu-Sánchez, 2009, p. 52; Osawa & McLaughlin, 2010, p. 111; Vargas-Zamora et al , 2012, p. 1766.…”