The distribution of L. depurator has been analysed through classical statistics, linear models and geostatistics. Density was obtained from a ten-year time series of bottom, otter trawl surveys in eight areas along the Mediterranean coast of Spain. Two peaks of L. depurator occurrence were observed. The first (80% occurrence) between 51 and 150 m, and the other (66% occurrence) between 301 and 400 m. Below 500 m, crab occurrence was negligible (<8%) and densities fell sharply. The pattern shown by crab densities closely shadows that of occurrence, although a second abundance peak was barely evident, and was located at 201- 300 m. From 200-400 m, crab abundance appeared fairly evenly distributed but showing lower densities than in shallower waters.
Analysis through linear modelling showed that L. depurator density decreased significantly with depth and year, but no effect of sample location was evident. The decrease of L. depurator density was most pronounced at shallower depths
 ( depths < 150 m, declining at ~8± 1 % per annum), than in deeper waters (depths> 150 m, declining at ~4±1 % per annum).
Geostatistical analysis of L. depurator densities showed that the crabs distributions exhibited varying degrees of spatial structure with patch sizes varying between 19 and 75 km among the sampled years. When average densities were low, crabs were most abundant in Ebro River Delta area and Western Alborán Sea, areas showing permanent high-density populations. The virtues and drawbacks of each approach are discussed.
On a smaller scale, off the Ebro Delta L. depurator distribution (numbers and biomass) was related to sediment characteristics using geostatistics. Smaller crabs were found preferentially in shallower water, whereas larger crabs, in deeper ones.
Given the presence of at least two distinctive aggregations (possible populations) of L. depurator on the Spanish coast, a series of morphometric studies were undertaken. A combination of traditional dimension analysis and geometric morphometry (whole shape analysis) was used to compare crab morphology. Differences in carapace shape were identified between genders and geographic location that largely appeared to involve the abdomen width.