Table 2. Benthic bathomes and the ecological and biological events used to define them.

Bathome (m) Depth Range	Ecological and Biological Events. Unless otherwise stated, the Bivalvia, Gastropoda, Isopoda and Polychaeta taxa discussed only include the species studied in Brandt et al. [37].
0–100	Seaweed availability limits depth of herbivores [131].
	Polychaete species richness is highest.
	12 paramunnid species and 8 genera of Isopod family Paramunnidae are restricted to the top 100 m (S. Kaiser, unpublished data).
	4 pycnogonid species have been recorded exclusively from the top 100 m [132]
100–200	200 m is likely to be the maximum extent of the influence of wave action and sunlight penetration [64].
	Polychaete species richness begins to rapidly decrease.
	Chlorophyll concentration is generally negligible below 200 m [83].
200–500	High gastropod species richness at approximately 200 m–300 m.
	The end of the depth range of Channichthys rhinoceratus which is located in depths less than 200 m [38].
	200–500 m is the depth range of Champsocephalus gunnari [38], [133].
	Zanclorhynchus spinifer depth range begins [38].
	500 m is the approximate maximum depth of scouring by contemporary ice bergs [42], [43], [134].
	Lepidonotothen squamifrons exhibits some areas of high density close to the 500 m isobath [38].
	Species of the isopod family, Santiidae are only found in the top 500 m.
	Most hydroid species only occur above 500 m [135]
500–1000	Upper slope mollusc assemblage is present between 400 and 800 m [136].
	Many echinoid species can only be found in the top 1000 m see suppl. Material of [28] and [137].
	Many bryozoan species restricted to the top 1000 m [53].
	Seven fold less gastropod species than at 200–300 m.
	The bivalve families Arcidae and Vesicomyidae can now be found. Condylocardiidae, Nuculidae, Hiatellidae and Erycinidae are no longer found.
	The Polychaeta families; Dorvilleidae, Chaetopteridae, Lacydoniidae, Pectinariidae and Spintheridae are no longer found.
	Much lower densities of fish than depths <500 m [133]. Four fish-depth ranges begin (Bathyraja eatonii, Bathyraja irrasa, Alepocephalus cf. Antipodianus and Etmopterus cf. granulosus) [38]. Z. spinifer depth range ends [38]. Sterechinus neuymeyeri depth range is between 0–810 m [40].
	Most pycnogonid species (63.8%) occur above 1000 m [132].
1000–1500	Bivalves, gastropods and polychaete diversity decreases from the shelf to the slope then stabilises at low numbers. There is no observed replacement of diminished shelf polychaete species from the slope and rise community (A. Brandt, unpublished data). The bivalve famillies Arcidae (Bathyarca sinuata) and Vesicomyidae (Vesicomya sirenkoi) can now be found regularly down to the abyss.
	The number of isopod species increases. Isopod families, Macrostylidae, Ischnomesidae and Haploniscidae are mostly found below 1000 m depth (with the exception of a few species found at shallower depths).
	Chaetognaths become much less abundant [138].
1500–2000	The gastropod families; Acetonidae, Cancellariidae and Cerithiidae are no longer found.
	The bivalve families; Pectinidae, Lyonsiidae and Astartidae are mostly only found down to 2000 m.
	Sequenziidae (gastropod) and Cyamiidae (bivalve) are located in depths shallower than 1500 m and deeper than 2000 m.
	ANDEEP samples showed isopod species typical of the shelf to penetrate to a depth of 1500–2000 m [139].
	Presence of a lower slope mollusc assemblage between 800 to 2000 m [136].
2000–3000	Depth band in which the gastropod family, Marginellidae is located (also located at depths <800 m). Also, the family Propilidiidae can now be found.
	The shelf inhabiting bivalve family Philobryidae is generally found in shallow water (<2000 m). However, the genus Adarcnarca can be found deeper than 2000 m.
	Isopod species richness continues to increase. The Isopod family, Austrarcturellidae is no longer found and Gnathiidae is found above and below this range.
	The main depth range of the polychaete family Pectinariidae (beside <500 m). Also, the Sabellariidae begin to be located (beside <200 m) and Eunicidae are no longer found.
3000–4500	Isopod species richness is highest within this depth range.
	Number of gastropod and polychaete species per depth begins to decrease.
	Echinoid species Echinosigra amphora and Pourtalesia debilis only occur between 3000 m and 4000 m [137].
	Gastropod species richness becomes extremely low and the gastropod families, Volutomitridae, Trichotropidae, Pleurobranchiidae, Fissurellidae are no longer found.
	The Isopoda families, Bopyridae and Stenetriidae are no longer found.
	The polychaete families, Pectinariidae are no longer found and Apistobranchidae end close to 3000 m.
	The bivalve families, Malletiidae and a species of Kelliidae are found deeper than around 3000 m.
	Only six bryozoan species occur below 3000 m [53].
	Polychaetes are now a deep-sea assemblage composed of genera considered typical within the deep sea worldwide. This shift begins at approximately 2500–3000 m and extends onto the abyssal plain [22]
4500+	Isopod and polychaete species richness drops rapidly. However this could also be due to sampling bias, as there are very few samples deeper than 5000 m. Isopoda families: Cirolanidae, Dendrotionidae, Gnathiidae, Paramunnidae and Xostylus incertae sedis are no longer found within samples.