Papers by William Santana
The complete larval stages of Notolopas brasiliensis are described from laboratory reared materia... more The complete larval stages of Notolopas brasiliensis are described from laboratory reared material, with emphasis on the external morphological features of Majoidea, and compare the morphology of N. brasiliensis with other genera of Pisidae. Larval development of N. brasiliensis consists of two zoeal stages and one megalopa. The duration mean of each zoeal stage was 4.2 ± 1.0 days for Zoea I and 3.8 ± 0.7 days for Zoea II, the megalopa instar appearing 8.1 ± 0.4 days after hatching. The characters previously used to define larval forms of Pisidae are either symplesiomorphic or potentially highly homoplastic. As well, was observed that there are no common sets of larval characters that would define Pisidae nowadays. However, was showed that only a combination of characters could differentiate Notolopas from other pisid genera.
Journal of Natural History, 2006
Pseudomicippe varians Miers, 1879 is a majid crab recorded from Western Australia (Shark Bay) and... more Pseudomicippe varians Miers, 1879 is a majid crab recorded from Western Australia (Shark Bay) and northern Queensland. The zoeal stages are described from laboratory reared material. The zoeal stages of P. varians can be easily distinguished by the absence of carapace spines and extremely large mandibles. These characters are likely diagnostic among majoideans in general. Additionally, recent phylogenetic studies of majoids using larval characters showed the Majidae as one of the few families for which there is larval support for its monophyly. Furthermore, based on the monophyly of Majidae and the morphology of P. varians, a set of characters is established that could be used as a diagnostic for majids in general.
A new species of Euprognatha Stimpson, 1871 from off coast of Brazil (Canopus Bank, 02°15.3'00"S ... more A new species of Euprognatha Stimpson, 1871 from off coast of Brazil (Canopus Bank, 02°15.3'00"S -38°16.0'00"W) is described and illustrated, namely Euprognatha limatula n. sp. The new species is compared to its congeners. Lectotypes are designated for E. acuta A. E. granulata Faxon, 1893. A key to the species of Euprognatha is provided.
The genus Scyllarides is found in tropical and subtropical regions, with 5 species occurring in t... more The genus Scyllarides is found in tropical and subtropical regions, with 5 species occurring in the Western Atlantic -Scyllarides aequinoctialis, S. brasiliensis, S. deceptor, S. delfosi, and S. nodifer. Existing information regarding their distribution is contradictory. Larvae of S. aequinoctialis and adults S. brasiliensis and S. delfosi are recorded for the first time from Brazil (Northeast offshore region and Santa Catarina and Rio Grande do Sul states, respectively). The fourth larval stage of S. aequinoctialis is described herein. The geographic distribution of the genus Scyllarides in the Western Atlantic is reevaluated based on museum material and published information.
Journal of Natural History, 2004
Apiomithrax violaceus (A. Milne Edwards, 1868) is a pisid majoid crab occurring in tropical and s... more Apiomithrax violaceus (A. Milne Edwards, 1868) is a pisid majoid crab occurring in tropical and subtropical coastal waters of the eastern and western South Atlantic. Larval development consists of two zoeal stages and a megalopa. Beginning with the first zoea, the duration of each larval stage at 24 ‡C was 3-8 (5¡1), 3-5 (4¡0.5) and 9-15 (11¡2) days, the megalopa and first crab instar appearing 9-11 (10¡1) and 20-27 (23¡2) days after hatching, respectively. Larval characters agree with those proposed for the Majoidea, in having nine or more setae on the scaphognathite in the first zoea and well-developed pleopods in the second zoea. However, larvae of A. violaceus do not fit larval pisid features. Zoeal stages differ from most other Pisidae in having lateral spines, a long rostral spine extending beyond the antenna, two spines per telson fork and a dorsolateral process on the third abdominal somite. The megalopa differs in having a spine dorsally on the carapace and on the basial segment of the second pereiopod. Two characters that are potentially unique to Apiomithrax include a zoeal antenna with an exopod that is much longer than the protopod, and a rostral spine that is longer than the dorsal spine. These characters should facilitate the identification of this taxon and could also be useful for phylogenetic studies. A review of larvae of 28 species among 14 genera indicated that there is no apparent single larval character that differentiates the Pisidae, with more limited phylogenetic analyses suggesting that this is a paraphyletic group. Apiomithrax, Eurynolambrus, Pisoides, Rochinia and Scyra have the most divergent morphological characters within the family. The analysis and inclusion of additional taxa is likely to shed more light on the sister-group relationships of the Pisidae. However, based on the extent of morphological interspecific variability of known larvae it is likely that the group, as presently defined by adult morphology, is not monophyletic.
Journal of Plankton Research, 2004
or mud bottoms from the intertidal zone to 180 m. We describe all laboratory-reared larval stages... more or mud bottoms from the intertidal zone to 180 m. We describe all laboratory-reared larval stages of S. furcatus obtained from the northern coast of Sao Paulo State, Brazil, and compare our data with existing larval descriptions for the genus and other mithracids. The larval development of S. furcatus consists of two zoeal stages and one megalopa. The durations of the first and second zoeal stage were ~4 and 5 days respectively, the megalopa appearing 10-18 days after hatching. Our results show that the zoeae of S. furcatus differ from those of other Mithracidae by possessing four setae on the proximal lobe of the coxal endite of the maxilla, instead of five, and by the presence of mid-dorsal setae on the third abdominal somite in the second zoeal stage, which are lacking in other mithracids. Larval descriptions for Stenocionops in two previous publications were attributed to the subspecies S. furcatus coelatus from the Caribbean. Larvae from Brazilian waters closely resemble one of these accounts, suggesting that this taxon extends beyond the West Indies and that the other description represents larvae of S. furcatus furcatus. Additional morphological details, not available previously, are provided.
Invertebrate Reproduction & Development, 2003
Mithrax hispidus (Herbst, 1790) is a mithracid majoid crab occurring on sand, corals and rocks in... more Mithrax hispidus (Herbst, 1790) is a mithracid majoid crab occurring on sand, corals and rocks in waters of the western Atlantic. Larval development consists of two zoeal stages and a megalopa. All larval stages are described in detail based on multiple cultures. Prior to this study, larvae of M. hispidus were considered to be different and grouped separately from most other larvae of Mithrax, primarily based on setation. A detailed morphological examination, based on the same specimens used for the first description, revealed that the inclusion of M. hispidus in a separate group is not valid as zoeae now fully agree with the morphological characteristics defined for the other group of five Mithrax species, including M. pleuracanthus, M. verrucosus, M. caribbaeus, M. coryphe, and M. forceps. This illustrates the importance of precisely recording morphological details such as setation, which may otherwise lead to incorrect interpretations with regard to perceived taxonomic affinities. A comparison of larvae of the Mithrax-Mithraculus species complex does not support separation into two genera. Larval evidence supports the recently suggested adult-based synonymization of M. caribbaeus with M. hispidus.
Abstract Within the recently resurrected family Inachoididae is Leurocyclus tuberculosus, an inac... more Abstract Within the recently resurrected family Inachoididae is Leurocyclus tuberculosus, an inachoidid spider crab distributed throughout the Western Atlantic of South America from Brazil to Argentina (including Patagonia), and along the Eastern Pacific coast of Chile. The larval development of L. tuberculosus consists of two zoeal stages and one megalopa. We observed that the larval morphology of L. tuberculosus conforms to the general pattern found in Majoidea by having two zoeal stages, in which the first stage has nine or more seta on ...
Uploads
Papers by William Santana