The biology of Austinixa gorei (Manning & Felder, 1989) (Decapoda, Brachyura, Pinnotheridae) symbiotic in the burrows of intertidal ghost shrimp (Decapoda, Thalassinidea, Callianassidae) in Miami, Florida

[The pinnotherid crab, Austinixa gorei lives in the burrows of ghost shrimp (infraorder Thalassinidea). Crabs were collected from ghost shrimp burrows in sandy, intertidal locations at Virginia Key and Key Biscayne, Florida from December 1966 to May, 1967. Gilvossius setimanus was the only ghost shrimp identified at these locations. Sexual pairs of crabs (considered the normal condition) occurred in 24 burrows, but most of the crabs were taken as single individuals, presumably due to sampling difficulties. The overall prevalence of one or more crabs per burrow was 100%. Male/female ratio was 0.75 (n = 54 and 72, respectively), and there was no significant difference in mean carapace width (CW) between the sexes (males 6.7 ± 1.7 mm; females 6.8 ± 1.5 mm). Carapace width was positively correlated with carapace length and abdomen width (AW). Females with AW/CW ratios of approximately ≥ 0.65 were mature. Ovigerous crabs (7.6 ± 0.7 mm CW) occurred at each collection date, but most were found in April and May. Numbers of embryos per brood were positively correlated with CW; maximum number per brood was 525. Some ovigerous crabs that were isolated in the laboratory produced one or two additional broods, with development to the first zoeae in approximately one month. Sperm remain viable in seminal receptacles for subsequent broods and molts. Increments of CW increase following molting were inversely correlated with CW. The gill chambers of five females of Austinixa gorei were infested with unidentified symbiotic nemerteans (Carcinonemertidae), broods of which occurred with the broods of two crabs. Six crabs were internally infected with unidentified parasitic isopods (Entoniscidae). Le crabe Pinnotheridae, Austinixa gorei vit dans les terriers de thalassinides. Des crabes ont ete recoltes dans des terriers de thalassinides dans la zone intertidale sableuse a Virginia Key et Key Biscayne, Floride, de decembre 1966 a mai 1967. Gilvossius setimanus etait le seul thalassinide identifie dans ces sites. Des couples (consideres comme la condition normale) etaient presents dans 24 terriers, mais la plupart des crabes ont ete captures en tant qu'individus isoles, sans doute en raison des difficultes d'echantillonnage. La prevalence totale d'un ou plus de crustaces par terrier etait de 100%. Le rapport mâle/femelle etait de 0,75 (n =54 et 72, respectivement), et il n'y avait pas de difference significative de la largeur moyenne de la carapace (CW) entre les sexes (mâles 6,7 ± 1,7 mm ; femelles 6,8 ± 1,5 mm). La largeur de la carapace etait correlee positivement a la longueur de la carapace et a la largeur de l'abdomen (AW). Les femelles presentant des rapports AW/CW d'environ > 0,65 etaient matures. Les femelles ovigeres (7,6 ± 0,7 mm CW) etaient presentes a chaque periode de recolte, mais la plupart ont ete trouvees en avril et mai. Les nombres d'embryons par ponte etaient correles positivement a CW, le maximum par ponte etait de 525. Quelques crabes femelles ovigeres isolees au laboratoire, ont produit une ou deux pontes supplementaires, avec developpement de la premiere zoe en approximativement un mois. Les spermatozoides restent viables dans les receptacles seminaux pour les pontes et mues suivantes. Les augmentations de CW apres la mue etaient inversement correlees a CW. Les chambres branchiales de cinq femelles d' Austinixa gorei etaient infestees de nemertes symbiotiques non identifies (Carcinonemertidae), dont les pontes etaient presentes avec celles de deux crabes. Six crabes etaient parasites par des isopodes parasites internes non identifies (Entoniscidae). , The pinnotherid crab, Austinixa gorei lives in the burrows of ghost shrimp (infraorder Thalassinidea). Crabs were collected from ghost shrimp burrows in sandy, intertidal locations at Virginia Key and Key Biscayne, Florida from December 1966 to May, 1967. Gilvossius setimanus was the only ghost shrimp identified at these locations. Sexual pairs of crabs (considered the normal condition) occurred in 24 burrows, but most of the crabs were taken as single individuals, presumably due to sampling difficulties. The overall prevalence of one or more crabs per burrow was 100%. Male/female ratio was 0.75 (n = 54 and 72, respectively), and there was no significant difference in mean carapace width (CW) between the sexes (males 6.7 ± 1.7 mm; females 6.8 ± 1.5 mm). Carapace width was positively correlated with carapace length and abdomen width (AW). Females with AW/CW ratios of approximately ≥ 0.65 were mature. Ovigerous crabs (7.6 ± 0.7 mm CW) occurred at each collection date, but most were found in April and May. Numbers of embryos per brood were positively correlated with CW; maximum number per brood was 525. Some ovigerous crabs that were isolated in the laboratory produced one or two additional broods, with development to the first zoeae in approximately one month. Sperm remain viable in seminal receptacles for subsequent broods and molts. Increments of CW increase following molting were inversely correlated with CW. The gill chambers of five females of Austinixa gorei were infested with unidentified symbiotic nemerteans (Carcinonemertidae), broods of which occurred with the broods of two crabs. Six crabs were internally infected with unidentified parasitic isopods (Entoniscidae). Le crabe Pinnotheridae, Austinixa gorei vit dans les terriers de thalassinides. Des crabes ont ete recoltes dans des terriers de thalassinides dans la zone intertidale sableuse a Virginia Key et Key Biscayne, Floride, de decembre 1966 a mai 1967. Gilvossius setimanus etait le seul thalassinide identifie dans ces sites. Des couples (consideres comme la condition normale) etaient presents dans 24 terriers, mais la plupart des crabes ont ete captures en tant qu'individus isoles, sans doute en raison des difficultes d'echantillonnage. La prevalence totale d'un ou plus de crustaces par terrier etait de 100%. Le rapport mâle/femelle etait de 0,75 (n =54 et 72, respectivement), et il n'y avait pas de difference significative de la largeur moyenne de la carapace (CW) entre les sexes (mâles 6,7 ± 1,7 mm ; femelles 6,8 ± 1,5 mm). La largeur de la carapace etait correlee positivement a la longueur de la carapace et a la largeur de l'abdomen (AW). Les femelles presentant des rapports AW/CW d'environ > 0,65 etaient matures. Les femelles ovigeres (7,6 ± 0,7 mm CW) etaient presentes a chaque periode de recolte, mais la plupart ont ete trouvees en avril et mai. Les nombres d'embryons par ponte etaient correles positivement a CW, le maximum par ponte etait de 525. Quelques crabes femelles ovigeres isolees au laboratoire, ont produit une ou deux pontes supplementaires, avec developpement de la premiere zoe en approximativement un mois. Les spermatozoides restent viables dans les receptacles seminaux pour les pontes et mues suivantes. Les augmentations de CW apres la mue etaient inversement correlees a CW. Les chambres branchiales de cinq femelles d' Austinixa gorei etaient infestees de nemertes symbiotiques non identifies (Carcinonemertidae), dont les pontes etaient presentes avec celles de deux crabes. Six crabes etaient parasites par des isopodes parasites internes non identifies (Entoniscidae). ]